diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4b5afa7a0f..a515115763 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,39 @@
 
 Detailed changelog for Perry. See CLAUDE.md for concise summaries.
 
+## v0.5.984 — feat(runtime): `.constructor` on Date / Array / Object instances + `new <inst.constructor>(...)` dispatch
+
+**Symptom.** date-fns 4.x throws `RangeError: Invalid time value` on the very first call to `format(new Date(2024, 0, 15), 'yyyy-MM-dd')`. Root cause is `constructFrom(date, value)` — the helper every other date-fns export funnels through:
+
+```js
+if (date instanceof Date) return new date.constructor(value);
+```
+
+Perry returned `undefined` from `date.constructor` (Date stores as a raw f64 timestamp, not an ObjectHeader, so the codegen receiver-tag guard at `pget.recv_bad` rejected it as non-pointer and short-circuited to `TAG_UNDEFINED` without ever calling the runtime). The downstream `new undefined(value)` then constructed an empty `ObjectHeader` placeholder; `cloned.getTime()` read garbage; the formatter threw.
+
+Same defect affected every duck-type test of the shape `inst.constructor === Date` / `arr.constructor === Array` / `obj.constructor === Object` (drizzle's `is(value, ctor)`, lodash-style `value.constructor === Array` checks, ramda’s `R.type` fast paths).
+
+**Fix.** Three coordinated changes so both `inst.constructor` reads and bare `Date` / `Array` / `Object` identifiers resolve to the same closure-pointer value, and so `new <inst.constructor>(...)` dispatches into the real factory.
+
+1. `crates/perry-hir/src/lower.rs` — bare built-in identifiers (`Date`, `Array`, `Object`, `Map`, `Set`, `Error`, …) now lower to `Expr::PropertyGet { GlobalGet(0), <name> }` instead of the bare `GlobalGet(0)` sentinel. Routes through the existing codegen `is_global_this_builtin_name` arm which materializes the singleton closure via `js_get_global_this` + `js_object_get_field_by_name_f64`. Added a parallel `is_builtin_global_value_name` helper in `crates/perry-hir/src/analysis.rs` that mirrors the codegen / runtime built-in lists. `lower_types.rs::lower_decorator_arg` extended to also recognise the new `PropertyGet { GlobalGet, name }` shape as a class ref for `@Decorator(Date)`-style use. Callable surfaces (`Date()`, `new Date(...)`, `Date.now()`, `Math.PI`) are intercepted by their dedicated HIR variants before this arm fires, so the change doesn’t disturb those.
+
+2. `crates/perry-runtime/src/object.rs::js_object_get_field_by_name` — new `"constructor"` short-circuit arms:
+   - `GC_TYPE_ARRAY` and `GC_TYPE_LAZY_ARRAY` → return `globalThis.Array` closure (was: returned `undefined`).
+   - Generic object path: `class_id == 0` → return `globalThis.Object`; `is_anon_shape_class_id(class_id)` → also `globalThis.Object` so `({ x: 1 }).constructor === Object` holds.
+   - Plus a new entry-level arm in `js_object_get_field_by_name_f64` that recognises raw-f64 Date receivers via `is_registered_date_bits` and returns `globalThis.Date` — needed because the codegen receiver-tag check filters Date out of the dispatch path otherwise.
+   - The codegen invalid-receiver fall-through (`pget.recv_bad`’s non-nullish branch) now routes through `js_object_get_field_by_name_f64` instead of emitting `TAG_UNDEFINED` directly, so the Date arm above actually fires for raw-f64 receivers.
+
+3. `crates/perry-runtime/src/object.rs::js_new_function_construct` — new `identify_global_builtin_constructor` short-circuit. Walks the singleton’s built-in entries, matches the receiver’s `ClosureHeader.func_ptr` against `global_this_builtin_noop_thunk` (GC-stable identifier — the singleton closure header itself gets evacuated and pointer-rewritten, but the embedded func ptr is read-only), and dispatches to the real factory:
+   - `Date` → `js_date_new` / `js_date_new_from_value` / `js_date_new_local_components`
+   - `Array` → `js_array_alloc` (single-finite-arg → empty array of that length; otherwise positional fill)
+   - `Object` → `js_object_alloc(0, 0)`
+
+   Plus a parallel codegen change in `crates/perry-codegen/src/expr.rs::NewDynamic`: callees of shape `PropertyGet { … }` (the date-fns `new date.constructor(value)` shape) now also route through `js_new_function_construct`. A statically-typed Date receiver short-circuits earlier to `Expr::DateNew(args)` so the hot path stays inline.
+
+4. `crates/perry-codegen/src/codegen.rs` — emit `js_register_anon_shape_class_id` at module init for every `__AnonShape_<hash>` class so the new constructor arm above can distinguish object-literal instances from user classes. The runtime exposes a matching `js_register_anon_shape_class_id` FFI declared in `crates/perry-codegen/src/runtime_decls.rs`, alongside the new `js_get_global_this_builtin_value` helper.
+
+**Validation.** `test-files/test_constructor_property.ts` covers Date / Array / Object `.constructor` reads, identity-equality with the bare global, and `new <date.constructor>(ts)` cloning — all 7 assertions match Node byte-for-byte. date-fns `format(new Date(...), 'yyyy-MM-dd')` (under `compilePackages: ["date-fns"]`) no longer trips `RangeError: Invalid time value`; the next blocker is a `Cannot read properties of undefined (reading 'map')` inside date-fns’s `normalizeDates` chain (downstream of `constructFrom` — separate gap).
+
 ## v0.5.983 — feat(runtime): `Function.prototype.apply` + `Function.prototype.call` dispatch
 
 **Symptom.** `add.apply(null, [2, 3])` and `add.call(null, 2, 3)` both returned an opaque `[object Object]` stub instead of `5`. The dynamic method-dispatch path (`js_native_call_method` in `crates/perry-runtime/src/object.rs`) had a `bind` arm and the closure dynamic-prop lookup, but no `apply` / `call` arms — so any `fn.apply(thisArg, argsArr)` / `fn.call(thisArg, …)` on a closure receiver fell through the `is_closure` branch and returned the `NULL_OBJECT_BYTES` stub. This is what blocked ramda end-to-end: `_curry1`, `_curry2`, `_curry3` all wrap their bodies in `fn.apply(this, arguments)`, so the very first call to any curried export (`R.sum`, `R.add`, etc.) returned a stub instead of the dispatch result.
diff --git a/CLAUDE.md b/CLAUDE.md
index 4cda55b8f2..aff98fbae7 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -8,7 +8,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 Perry is a native TypeScript compiler written in Rust that compiles TypeScript source code directly to native executables. It uses SWC for TypeScript parsing and LLVM for code generation.
 
-**Current Version:** 0.5.983
+**Current Version:** 0.5.984
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index 97838646d9..3467067187 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4905,7 +4905,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "base64",
@@ -4960,14 +4960,14 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "log",
@@ -4980,7 +4980,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -4989,7 +4989,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -4997,7 +4997,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5007,7 +5007,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5016,7 +5016,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "base64",
@@ -5029,7 +5029,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5037,7 +5037,7 @@ dependencies = [
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "serde",
  "serde_json",
@@ -5045,7 +5045,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.983"
+version = "0.5.984"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5056,7 +5056,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "clap",
@@ -5071,7 +5071,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5079,7 +5079,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5088,7 +5088,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5096,7 +5096,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5104,7 +5104,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5112,14 +5112,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "chrono",
  "cron",
@@ -5128,7 +5128,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5136,7 +5136,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5144,7 +5144,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5152,7 +5152,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "rand 0.8.6",
@@ -5160,21 +5160,21 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5188,7 +5188,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5199,7 +5199,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lazy_static",
  "perry-ext-http-server",
@@ -5211,7 +5211,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http-server"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5230,7 +5230,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5240,7 +5240,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "base64",
  "jsonwebtoken",
@@ -5251,7 +5251,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -5259,7 +5259,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5267,7 +5267,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "bson",
  "futures-util",
@@ -5279,7 +5279,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5289,7 +5289,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -5298,7 +5298,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "rustls",
@@ -5309,7 +5309,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -5319,7 +5319,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -5328,7 +5328,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -5336,7 +5336,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "base64",
  "image",
@@ -5345,14 +5345,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-slugify"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5360,7 +5360,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -5368,7 +5368,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -5378,7 +5378,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -5389,7 +5389,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "flate2",
  "perry-ffi",
@@ -5397,7 +5397,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "dashmap 6.1.0",
  "once_cell",
@@ -5406,7 +5406,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -5420,7 +5420,7 @@ dependencies = [
 
 [[package]]
 name = "perry-jsruntime"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "deno_core",
@@ -5440,7 +5440,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -5452,7 +5452,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "base64",
@@ -5476,7 +5476,7 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "aes 0.8.4",
  "aes-gcm",
@@ -5546,7 +5546,7 @@ dependencies = [
 
 [[package]]
 name = "perry-transform"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5556,7 +5556,7 @@ dependencies = [
 
 [[package]]
 name = "perry-types"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "anyhow",
  "thiserror 1.0.69",
@@ -5564,11 +5564,11 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.983"
+version = "0.5.984"
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "itoa",
  "jni",
@@ -5583,7 +5583,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "rand 0.8.6",
  "serde",
@@ -5593,7 +5593,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "cairo-rs",
  "dirs 5.0.1",
@@ -5612,7 +5612,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "block2",
  "libc",
@@ -5627,7 +5627,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "block2",
  "libc",
@@ -5645,11 +5645,11 @@ version = "0.1.0"
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.983"
+version = "0.5.984"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "block2",
  "libc",
@@ -5664,7 +5664,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "block2",
  "libc",
@@ -5679,7 +5679,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "block2",
  "libc",
@@ -5692,7 +5692,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "libc",
  "perry-runtime",
@@ -5706,7 +5706,7 @@ dependencies = [
 
 [[package]]
 name = "perry-updater"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "base64",
  "ed25519-dalek",
@@ -5720,7 +5720,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.983"
+version = "0.5.984"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index be87877e91..f5767a9bc6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -190,7 +190,7 @@ opt-level = "s"       # Optimize for size in stdlib
 opt-level = 3
 
 [workspace.package]
-version = "0.5.983"
+version = "0.5.984"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/crates/perry-codegen/src/codegen.rs b/crates/perry-codegen/src/codegen.rs
index 0851036fe7..096742274f 100644
--- a/crates/perry-codegen/src/codegen.rs
+++ b/crates/perry-codegen/src/codegen.rs
@@ -5638,6 +5638,7 @@ fn emit_string_pool(
     // and similar method-less marker classes hit this.
     {
         let mut all_class_ids: Vec<u32> = Vec::new();
+        let mut anon_shape_ids: Vec<u32> = Vec::new();
         for (class_name, class) in classes.iter() {
             if *class_name != class.name {
                 continue;
@@ -5647,6 +5648,16 @@ fn emit_string_pool(
                 _ => continue,
             };
             all_class_ids.push(cid);
+            // date-fns / drizzle / lodash plain-object duck-checks need
+            // `({ x: 1 }).constructor === Object` to hold. The HIR
+            // synthesizes an `__AnonShape_<hash>` class per literal
+            // shape; mark each such class id so the runtime
+            // `js_object_get_field_by_name` resolves `.constructor` to
+            // the global `Object` constructor instead of the synthetic
+            // class ref.
+            if class_name.starts_with("__AnonShape_") {
+                anon_shape_ids.push(cid);
+            }
         }
         all_class_ids.sort_unstable();
         all_class_ids.dedup();
@@ -5656,6 +5667,14 @@ fn emit_string_pool(
                 &[(crate::types::I32, &cid.to_string())],
             );
         }
+        anon_shape_ids.sort_unstable();
+        anon_shape_ids.dedup();
+        for cid in anon_shape_ids {
+            blk.call_void(
+                "js_register_anon_shape_class_id",
+                &[(crate::types::I32, &cid.to_string())],
+            );
+        }
     }
 
     // Refs #486 (hono logger middleware): also register every class
diff --git a/crates/perry-codegen/src/expr.rs b/crates/perry-codegen/src/expr.rs
index 78f8437459..858caf1715 100644
--- a/crates/perry-codegen/src/expr.rs
+++ b/crates/perry-codegen/src/expr.rs
@@ -3670,6 +3670,34 @@ pub(crate) fn lower_expr(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
         // (which IS the NaN-boxed value for non-number fields — same bit
         // pattern, runtime callers re-interpret based on context).
         Expr::PropertyGet { object, property } => {
+            // date-fns `constructFrom(date, value)` reads `date.constructor`
+            // to clone Dates without naming Date directly. Perry stores
+            // Date as a raw f64 timestamp (no ObjectHeader), so the
+            // generic `js_object_get_field_by_name_f64` path would treat
+            // the bit pattern as an invalid pointer and return undefined.
+            // For statically-Date-typed receivers, short-circuit
+            // `.constructor` to the global Date constructor closure —
+            // same value as the bare `Date` identifier resolves to via
+            // `js_get_global_this_builtin_value`.
+            if property == "constructor" {
+                if let Expr::LocalGet(id) = object.as_ref() {
+                    let is_date = matches!(
+                        ctx.local_types.get(id),
+                        Some(HirType::Named(name)) if name == "Date"
+                    );
+                    if is_date {
+                        let name = "Date";
+                        let idx = ctx.strings.intern(name);
+                        let bytes_global = format!("@{}", ctx.strings.entry(idx).bytes_global);
+                        let len_str = name.len().to_string();
+                        return Ok(ctx.block().call(
+                            DOUBLE,
+                            "js_get_global_this_builtin_value",
+                            &[(PTR, &bytes_global), (I64, &len_str)],
+                        ));
+                    }
+                }
+            }
             // Issue #649: PropertyGet on a native-module reference (`fs`,
             // `os`, `crypto`, `path`, ...). `NativeModuleRef` lowers to a
             // literal `0.0`, so the generic PropertyGet path can't see the
@@ -4456,10 +4484,21 @@ pub(crate) fn lower_expr(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
             ctx.block().unreachable();
 
             // Undef-return path: existing fall-through for non-nullish
-            // invalid receivers.
+            // invalid receivers. Route through the runtime helper first
+            // so non-pointer typed shapes can still report a sensible
+            // value when the runtime knows what they are. Today this
+            // unblocks Date `.constructor` (Date stores as a raw f64
+            // timestamp, so the codegen receiver-tag check at line ~4212
+            // rejects it as non-pointer — yet the runtime's
+            // `js_object_get_field_by_name_f64` recognizes the bit
+            // pattern via `DATE_REGISTRY` and returns the global Date
+            // constructor closure). Date-fns `constructFrom` blocker.
             ctx.current_block = undef_idx;
-            let undef_bits = crate::nanbox::i64_literal(crate::nanbox::TAG_UNDEFINED);
-            let undef_val = ctx.block().bitcast_i64_to_double(&undef_bits);
+            let undef_val = ctx.block().call(
+                DOUBLE,
+                "js_object_get_field_by_name_f64",
+                &[(I64, &obj_bits), (I64, &key_handle)],
+            );
             let invalid_end_label = ctx.block().label.clone();
             ctx.block().br(&final_merge_label);
 
@@ -5104,6 +5143,31 @@ pub(crate) fn lower_expr(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
                 return lower_new(ctx, name, args);
             }
 
+            // date-fns `constructFrom(date, value)`:
+            //   return new date.constructor(value);
+            // The callee is `PropertyGet { LocalGet(date), "constructor" }`
+            // where `date` is statically Date-typed. Lower through the
+            // dedicated `Expr::DateNew` path so the call routes to
+            // `js_date_new_from_value` / `js_date_new_local_components`
+            // and the result is a real Date timestamp, not an empty
+            // ObjectHeader. Pre-fix the NewDynamic fallback returned a
+            // placeholder object — `cloned.getTime()` then read garbage
+            // and the equality failed. Refs date-fns blocker.
+            if let Expr::PropertyGet { object, property } = callee.as_ref() {
+                if property == "constructor" {
+                    if let Expr::LocalGet(id) = object.as_ref() {
+                        let is_date = matches!(
+                            ctx.local_types.get(id),
+                            Some(HirType::Named(name)) if name == "Date"
+                        );
+                        if is_date {
+                            let synth = Expr::DateNew(args.to_vec());
+                            return lower_expr(ctx, &synth);
+                        }
+                    }
+                }
+            }
+
             // Refs #740: `new O.Inner(args)` where `O` is an object
             // literal whose `Inner` field was initialized from a class
             // expression. The Stmt::Let lowering populates
@@ -5175,8 +5239,18 @@ pub(crate) fn lower_expr(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
             // also supported because the helper falls back to a
             // class_id=0 empty-object allocation when no synthetic id
             // exists (preserves the pre-fix baseline).
-            let routes_through_function_construct =
-                matches!(callee.as_ref(), Expr::FuncRef(_) | Expr::LocalGet(_));
+            // Also route PropertyGet callees through `js_new_function_construct`:
+            // covers `new date.constructor(value)` (date-fns
+            // `constructFrom`) and generic `new obj.factory(...)` shapes
+            // where `obj.factory` resolves to a closure pointer at
+            // runtime. The runtime helper detects the global Date /
+            // Array / Object thunks and dispatches into the matching
+            // real factory; non-matching closures still get the
+            // class_id=0 empty-object baseline.
+            let routes_through_function_construct = matches!(
+                callee.as_ref(),
+                Expr::FuncRef(_) | Expr::LocalGet(_) | Expr::PropertyGet { .. }
+            );
             if routes_through_function_construct {
                 let func_double = lower_expr(ctx, callee)?;
                 let lowered_args: Vec<String> = args
diff --git a/crates/perry-codegen/src/runtime_decls.rs b/crates/perry-codegen/src/runtime_decls.rs
index e7f66e7322..edbd3c0f0b 100644
--- a/crates/perry-codegen/src/runtime_decls.rs
+++ b/crates/perry-codegen/src/runtime_decls.rs
@@ -696,6 +696,17 @@ pub fn declare_phase_b_strings(module: &mut LlModule) {
     module.declare_function("js_instanceof_dynamic", DOUBLE, &[DOUBLE, DOUBLE]);
     module.declare_function("js_register_class_extends_error", VOID, &[I32]);
     module.declare_function("js_register_class_id", VOID, &[I32]);
+    // Anon-shape class registration so `.constructor` reads on object
+    // literals (`{ x: 1 }`) return the global `Object` constructor
+    // instead of the synthetic class ref. Refs #968 / date-fns
+    // `constructFrom` blocker.
+    module.declare_function("js_register_anon_shape_class_id", VOID, &[I32]);
+    // Built-in constructor / namespace value-lookup on the globalThis
+    // singleton. Used to wire `instance.constructor` and bare
+    // `Date`/`Array`/`Object` identifiers to the same closure pointer
+    // so `inst.constructor === Date` (date-fns / drizzle / lodash duck
+    // checks) holds.
+    module.declare_function("js_get_global_this_builtin_value", DOUBLE, &[PTR, I64]);
     // Inline-allocator class registration: emitted once per class
     // with a parent in the entry-block init prelude. The runtime
     // allocators register on every alloc; the inline allocator skips
diff --git a/crates/perry-hir/src/analysis.rs b/crates/perry-hir/src/analysis.rs
index f03a87e5de..f17d46c56a 100644
--- a/crates/perry-hir/src/analysis.rs
+++ b/crates/perry-hir/src/analysis.rs
@@ -1317,6 +1317,60 @@ pub(crate) fn is_builtin_function(name: &str) -> bool {
     )
 }
 
+/// Built-in constructor / namespace identifiers that should resolve to
+/// a real `globalThis.<Name>` closure pointer when used as a bare
+/// expression value (e.g. `inst.constructor === Date`, drizzle's
+/// `value.constructor === Object`, lodash's `var A = context.Array`).
+/// Mirrors `populate_global_this_builtins` in
+/// `crates/perry-runtime/src/object.rs` and
+/// `is_global_this_builtin_name` in `crates/perry-codegen/src/expr.rs`.
+///
+/// Callable surfaces — `Date()`/`new Date()`/`Date.now()`/`Math.PI` —
+/// are intercepted by dedicated HIR variants (`Expr::DateNow`,
+/// `Expr::DateNew`, `Expr::DateGet*`, `Expr::MathPow`, …) before the
+/// ident lowering reaches this point, so converting bare names to
+/// `PropertyGet { GlobalGet, name }` doesn't disturb those paths.
+pub(crate) fn is_builtin_global_value_name(name: &str) -> bool {
+    matches!(
+        name,
+        "Array"
+            | "Object"
+            | "String"
+            | "Number"
+            | "Boolean"
+            | "Function"
+            | "RegExp"
+            | "Date"
+            | "Error"
+            | "TypeError"
+            | "RangeError"
+            | "SyntaxError"
+            | "ReferenceError"
+            | "EvalError"
+            | "URIError"
+            | "Symbol"
+            | "Promise"
+            | "Map"
+            | "Set"
+            | "WeakMap"
+            | "WeakSet"
+            | "WeakRef"
+            | "Proxy"
+            | "BigInt"
+            | "Uint8Array"
+            | "Int8Array"
+            | "Uint16Array"
+            | "Int16Array"
+            | "Uint32Array"
+            | "Int32Array"
+            | "Float32Array"
+            | "Float64Array"
+            | "BigInt64Array"
+            | "BigUint64Array"
+            | "Uint8ClampedArray"
+    )
+}
+
 /// Rewrite all `Expr::This` references inside a block of statements to
 /// `Expr::LocalGet(this_id)`. Used to lift class generator methods
 /// (`*[Symbol.iterator]()`) to a top-level function with `this` as an
diff --git a/crates/perry-hir/src/lower.rs b/crates/perry-hir/src/lower.rs
index c111736cac..b2ef87334d 100644
--- a/crates/perry-hir/src/lower.rs
+++ b/crates/perry-hir/src/lower.rs
@@ -8216,6 +8216,25 @@ pub(crate) fn lower_expr(ctx: &mut LoweringContext, expr: &ast::Expr) -> Result<
                         name
                     );
                 }
+                // Bare built-in constructor identifiers (`Date`, `Array`,
+                // `Object`, ...) used as VALUES (not method receivers /
+                // `new` callees) need a real closure pointer so identity
+                // comparisons like `inst.constructor === Date` hold —
+                // both sides must resolve to the same `populate_global_this_builtins`-
+                // installed closure. Reuse the existing
+                // `PropertyGet { GlobalGet, <name> }` codegen path that
+                // dispatches through `js_get_global_this` for builtin
+                // names. Bare-callee shapes (e.g. `Date.now()`, `new
+                // Date()`) are picked off earlier by their dedicated HIR
+                // variants — `Expr::DateNow`, `Expr::DateNew(...)`,
+                // `Expr::Date*Get(...)` — so they don't reach this arm.
+                // date-fns / drizzle / lodash duck-typing path.
+                if is_builtin_global_value_name(&name) {
+                    return Ok(Expr::PropertyGet {
+                        object: Box::new(Expr::GlobalGet(0)),
+                        property: name,
+                    });
+                }
                 Ok(Expr::GlobalGet(0))
             }
         }
diff --git a/crates/perry-hir/src/lower_types.rs b/crates/perry-hir/src/lower_types.rs
index 3789694b51..e57ccc97c7 100644
--- a/crates/perry-hir/src/lower_types.rs
+++ b/crates/perry-hir/src/lower_types.rs
@@ -1232,6 +1232,16 @@ fn lower_decorator_arg(ctx: &mut LoweringContext, expr: &ast::Expr) -> Option<Ex
         ast::Expr::Lit(lit) => lower_lit(lit).ok(),
         ast::Expr::Ident(ident) => match lower_expr(ctx, expr).ok() {
             Some(Expr::GlobalGet(0)) => Some(Expr::ClassRef(ident.sym.to_string())),
+            // Bare built-in name `Date`/`Array`/`Object`/... now lowers
+            // to `PropertyGet { GlobalGet(0), name }` (so the value-side
+            // identity comparison `inst.constructor === Date` matches).
+            // For decorator-arg use it's still a class ref.
+            Some(Expr::PropertyGet {
+                object: ref obj,
+                property: _,
+            }) if matches!(obj.as_ref(), Expr::GlobalGet(0)) => {
+                Some(Expr::ClassRef(ident.sym.to_string()))
+            }
             other => other,
         },
         ast::Expr::Array(arr) => {
diff --git a/crates/perry-runtime/src/object.rs b/crates/perry-runtime/src/object.rs
index 7509f111c0..4265eb40ef 100644
--- a/crates/perry-runtime/src/object.rs
+++ b/crates/perry-runtime/src/object.rs
@@ -1236,6 +1236,99 @@ pub unsafe extern "C" fn js_register_class_id(class_id: u32) {
     guard.as_mut().unwrap().insert(class_id);
 }
 
+/// Resolve a closure-typed JSValue back to a built-in constructor name
+/// (`"Date"`/`"Array"`/`"Object"`/...) when it matches one of the
+/// singleton-installed thunks. Returns `None` for closures that aren't
+/// the globalThis built-in constructors. Used by
+/// `js_new_function_construct` to dispatch `new <inst.constructor>(...)`
+/// shapes (date-fns `constructFrom`, lodash-style `Array` cloning, ...)
+/// to the right runtime factory.
+fn identify_global_builtin_constructor(func_value: f64) -> Option<&'static str> {
+    use crate::value::JSValue;
+    let jv = JSValue::from_bits(func_value.to_bits());
+    if !jv.is_pointer() {
+        return None;
+    }
+    let ptr = jv.as_pointer() as *const crate::closure::ClosureHeader;
+    if ptr.is_null() {
+        return None;
+    }
+    if !is_valid_obj_ptr(ptr as *const u8) {
+        return None;
+    }
+    // Identify by the closure's read-only `func_ptr` rather than the
+    // GC-movable ClosureHeader address. Both the date-fns ctor closure
+    // and the (later-evacuated) ctor closure carry the same
+    // `global_this_builtin_noop_thunk` function pointer, so this match
+    // survives GC moves. The per-name lookup must then walk the
+    // globalThis singleton's keys to recover the constructor name —
+    // accept the extra hop only when the func_ptr matches.
+    unsafe {
+        if (*ptr).type_tag != crate::closure::CLOSURE_MAGIC {
+            return None;
+        }
+        let func_ptr = (*ptr).func_ptr as usize;
+        let noop_thunk = global_this_builtin_noop_thunk as *const u8 as usize;
+        if func_ptr != noop_thunk {
+            return None;
+        }
+    }
+    // Find which builtin name maps to this exact closure header on the
+    // singleton. Walk via the existing
+    // `js_get_global_this_builtin_value` helper — short loop (≤ ~50
+    // entries), only fires on the constructFrom hot path.
+    let global_this_f64 = js_get_global_this();
+    let global_obj = crate::value::js_nanbox_get_pointer(global_this_f64) as *const ObjectHeader;
+    if global_obj.is_null() {
+        return None;
+    }
+    for name in GLOBAL_THIS_BUILTIN_CONSTRUCTORS.iter().copied() {
+        let key = crate::string::js_string_from_bytes(name.as_ptr(), name.len() as u32);
+        let v = unsafe { js_object_get_field_by_name(global_obj, key) };
+        if v.bits() == jv.bits() {
+            return Some(name);
+        }
+    }
+    None
+}
+
+/// Synthetic-anonymous-shape class IDs: classes the HIR generates for
+/// bare object literals (`{ x: 1 }` → `__AnonShape_<hash>`). Instances
+/// of these shapes should report `Object` from `.constructor`, not the
+/// synthetic class itself, so date-fns's `new value.constructor(...)`,
+/// drizzle's `value.constructor === Object` duck checks, and the standard
+/// `({}).constructor === Object` semantics all match Node. The HIR
+/// lowering registers each anon shape's id here at module init.
+pub static ANON_SHAPE_CLASS_IDS: RwLock<Option<std::collections::HashSet<u32>>> = RwLock::new(None);
+
+/// Mark `class_id` as a synthetic anon-shape class so `.constructor`
+/// reads on instances of that class return the global `Object`
+/// constructor rather than the synthetic class ref.
+#[no_mangle]
+pub unsafe extern "C" fn js_register_anon_shape_class_id(class_id: u32) {
+    if class_id == 0 {
+        return;
+    }
+    let mut guard = ANON_SHAPE_CLASS_IDS.write().unwrap();
+    if guard.is_none() {
+        *guard = Some(std::collections::HashSet::new());
+    }
+    guard.as_mut().unwrap().insert(class_id);
+}
+
+/// True if `class_id` was registered via `js_register_anon_shape_class_id`.
+pub fn is_anon_shape_class_id(class_id: u32) -> bool {
+    if class_id == 0 {
+        return false;
+    }
+    if let Ok(guard) = ANON_SHAPE_CLASS_IDS.read() {
+        if let Some(set) = guard.as_ref() {
+            return set.contains(&class_id);
+        }
+    }
+    false
+}
+
 /// Register a static field value on a class so `Cls.field` (when `Cls` is
 /// accessed via dynamic dispatch — e.g. through an Any-typed local) finds
 /// the value via the runtime path. Codegen calls this at module init for
@@ -1429,6 +1522,62 @@ pub unsafe extern "C" fn js_new_function_construct(
     args_ptr: *const f64,
     args_len: usize,
 ) -> f64 {
+    // date-fns `constructFrom` clones a Date via
+    // `new date.constructor(value)`. `date.constructor` resolves to
+    // the global `Date` closure pointer (the noop thunk installed by
+    // `populate_global_this_builtins`). Without this intercept the
+    // call falls through to the generic empty-object path and
+    // `cloned.getTime()` reads garbage. Detect the global Date /
+    // Array / Object constructor pointers and dispatch into the
+    // matching real factory. Refs date-fns blocker.
+    if let Some(name) = identify_global_builtin_constructor(func_value) {
+        let args = if args_ptr.is_null() {
+            &[][..]
+        } else {
+            std::slice::from_raw_parts(args_ptr, args_len)
+        };
+        match name {
+            "Date" => {
+                if args.is_empty() {
+                    return crate::date::js_date_new();
+                }
+                if args.len() == 1 {
+                    return crate::date::js_date_new_from_value(args[0]);
+                }
+                let mut vals = [f64::from_bits(crate::value::TAG_UNDEFINED); 7];
+                for (i, slot) in vals.iter_mut().enumerate() {
+                    if i < args.len() {
+                        *slot = args[i];
+                    }
+                }
+                return crate::date::js_date_new_local_components(
+                    vals[0], vals[1], vals[2], vals[3], vals[4], vals[5], vals[6],
+                );
+            }
+            "Array" => {
+                // `new Array(n)`: empty array of length n.
+                // `new Array(a, b, c)`: array filled with the args.
+                let single_len = args.len() == 1 && args[0].is_finite() && args[0] >= 0.0;
+                let len = if single_len {
+                    args[0] as u32
+                } else {
+                    args.len() as u32
+                };
+                let arr = crate::array::js_array_alloc(len);
+                if !single_len {
+                    for (i, &v) in args.iter().enumerate() {
+                        crate::array::js_array_set_f64(arr, i as u32, v);
+                    }
+                }
+                return crate::value::js_nanbox_pointer(arr as i64);
+            }
+            "Object" => {
+                let obj = js_object_alloc(0, 0);
+                return crate::value::js_nanbox_pointer(obj as i64);
+            }
+            _ => {}
+        }
+    }
     let cid = synthetic_class_id_for_function(func_value);
     // Allocate the instance with the synthetic class id (or 0 if the
     // value isn't callable). The object starts with no own props; the
@@ -3803,6 +3952,16 @@ pub extern "C" fn js_object_get_field_by_name(
                     let arr = obj as *const crate::array::ArrayHeader;
                     return JSValue::number(crate::array::js_array_length(arr) as f64);
                 }
+                // date-fns / drizzle / lodash duck-typing path:
+                // `arr.constructor === Array`, `new arr.constructor(...)`,
+                // etc. expect a non-undefined function-typed value that
+                // refers back to the global `Array` constructor. Resolve
+                // through the singleton so this returns the same closure
+                // pointer as the bare `Array` identifier.
+                if key_bytes == b"constructor" {
+                    let v = js_get_global_this_builtin_value(b"Array".as_ptr(), 5);
+                    return JSValue::from_bits(v.to_bits());
+                }
             }
             return JSValue::undefined();
         }
@@ -3820,6 +3979,10 @@ pub extern "C" fn js_object_get_field_by_name(
                     let arr = obj as *const crate::array::ArrayHeader;
                     return JSValue::number(crate::array::js_array_length(arr) as f64);
                 }
+                if key_bytes == b"constructor" {
+                    let v = js_get_global_this_builtin_value(b"Array".as_ptr(), 5);
+                    return JSValue::from_bits(v.to_bits());
+                }
             }
             // Any other property access force-materializes, then
             // re-enters via the materialized ArrayHeader pointer.
@@ -3982,10 +4145,29 @@ pub extern "C" fn js_object_get_field_by_name(
             let key_bytes = std::slice::from_raw_parts(key_ptr, key_len);
             if key_bytes == b"constructor" {
                 let class_id = (*obj).class_id;
+                // Object-literal instances (`{ x: 1 }`) carry a synthetic
+                // `__AnonShape_*` class id. Spec says their `.constructor`
+                // is the global `Object`, not the synthetic class — so
+                // resolve through the globalThis singleton so the value
+                // matches the bare `Object` identifier (`x.constructor
+                // === Object`, date-fns `constructFrom`, drizzle's
+                // `isPlainObject` duck check).
+                if class_id != 0 && is_anon_shape_class_id(class_id) {
+                    let v = js_get_global_this_builtin_value(b"Object".as_ptr(), 6);
+                    return JSValue::from_bits(v.to_bits());
+                }
                 if class_id != 0 && is_class_id_registered(class_id) {
                     let bits = 0x7FFE_0000_0000_0000u64 | (class_id as u64);
                     return JSValue::from_bits(bits);
                 }
+                // class_id == 0 fallback: plain ObjectHeader allocated
+                // without an HIR shape (Object.create(null) hybrids, raw
+                // empty `{}` produced by JSON.parse, etc.). Report
+                // `Object` so duck-type tests don't trip undefined.
+                if class_id == 0 {
+                    let v = js_get_global_this_builtin_value(b"Object".as_ptr(), 6);
+                    return JSValue::from_bits(v.to_bits());
+                }
             }
         }
 
@@ -4275,6 +4457,26 @@ pub extern "C" fn js_object_get_field_by_name_f64(
     obj: *const ObjectHeader,
     key: *const crate::StringHeader,
 ) -> f64 {
+    // date-fns `constructFrom`: the parameter is statically Any so the
+    // codegen Date intercept doesn't fire here. Detect Date instances
+    // by their registered f64 bit pattern and route `.constructor` to
+    // the global Date constructor closure — same value the bare `Date`
+    // identifier produces, so `date instanceof Date` followed by `new
+    // date.constructor(value)` lands on the right factory inside
+    // `js_new_function_construct`.
+    if !key.is_null() {
+        let obj_bits = obj as u64;
+        if crate::date::is_registered_date_bits(obj_bits) {
+            unsafe {
+                let key_ptr = (key as *const u8).add(std::mem::size_of::<crate::StringHeader>());
+                let key_len = (*key).byte_len as usize;
+                let key_bytes = std::slice::from_raw_parts(key_ptr, key_len);
+                if key_bytes == b"constructor" {
+                    return js_get_global_this_builtin_value(b"Date".as_ptr(), 4);
+                }
+            }
+        }
+    }
     let value = js_object_get_field_by_name(obj, key);
     f64::from_bits(value.bits())
 }
@@ -10010,6 +10212,39 @@ fn populate_global_this_builtins(singleton: *mut ObjectHeader) {
     }
 }
 
+/// Look up the canonical NaN-boxed value of a built-in constructor /
+/// namespace stored on `globalThis` (the singleton populated by
+/// `populate_global_this_builtins`). Used by `instance.constructor`
+/// reads and by bare `Date`/`Array`/`Object` identifier resolution so
+/// both forms produce the same closure-pointer value — that's what
+/// `instance.constructor === Date` (date-fns's `constructFrom`,
+/// drizzle's `is(value, ctor)` duck checks, ...) hinges on.
+///
+/// Returns NaN-boxed undefined if the name isn't one of the populated
+/// built-ins or the singleton hasn't been initialized yet.
+#[no_mangle]
+pub extern "C" fn js_get_global_this_builtin_value(name_ptr: *const u8, name_len: usize) -> f64 {
+    if name_ptr.is_null() || name_len == 0 {
+        return f64::from_bits(crate::value::TAG_UNDEFINED);
+    }
+    let name_bytes = unsafe { std::slice::from_raw_parts(name_ptr, name_len) };
+    let name = match std::str::from_utf8(name_bytes) {
+        Ok(s) => s,
+        Err(_) => return f64::from_bits(crate::value::TAG_UNDEFINED),
+    };
+    // Force the singleton init the first time so the lookup below has
+    // a populated field bag.
+    let global_this_f64 = js_get_global_this();
+    let global_obj = crate::value::js_nanbox_get_pointer(global_this_f64) as *const ObjectHeader;
+    if global_obj.is_null() {
+        return f64::from_bits(crate::value::TAG_UNDEFINED);
+    }
+    let key = crate::string::js_string_from_bytes(name.as_ptr(), name.len() as u32);
+    let value = js_object_get_field_by_name(global_obj, key);
+    let bits = value.bits();
+    f64::from_bits(bits)
+}
+
 /// Object.getOwnPropertyNames(obj) — returns all own property names (including non-enumerable).
 /// Takes a NaN-boxed f64 object pointer, returns a NaN-boxed f64 array pointer.
 #[no_mangle]
diff --git a/test-files/test_constructor_property.ts b/test-files/test_constructor_property.ts
new file mode 100644
index 0000000000..a1b657f0ed
--- /dev/null
+++ b/test-files/test_constructor_property.ts
@@ -0,0 +1,13 @@
+const d = new Date(2024, 0, 15);
+console.log(typeof d.constructor);
+console.log(d.constructor === Date);
+const cloned = new (d.constructor as any)(d.getTime());
+console.log(cloned.getTime() === d.getTime());
+
+const arr = [1, 2, 3];
+console.log(typeof arr.constructor);
+console.log(arr.constructor === Array);
+
+const obj = { x: 1 };
+console.log(typeof obj.constructor);
+console.log(obj.constructor === Object);