diff --git a/CHANGELOG.md b/CHANGELOG.md
index b3d07ca5a1..661fce81db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## v0.5.1202 — revert: #5546 + #5553 (#5437 module-default wrapper auto-call machinery) — wrong layer, proven cannot close W6
+
+Reverts the auto-call wrapper-resolve machinery (#5546) and its boot-crash patch (#5553). A rigorous follow-up disproved the approach: the #5437 throw (`new uw.SharedCacheControls`) fails because the captured `uw` reads a **mis-boxed closure** at request time, whereas `uw` is a correct `module.exports` **object** at every point where the registration/auto-call could fire (the `require`, the class-capture store). So registering module-default wrappers is a guaranteed no-op for this bug — the value that throws never passes through a registration site. The machinery also introduced a regression (auto-calling a CJS function-export wrapper, e.g. `debug`, on the `_interop_require_default` `.__esModule` probe → boot crash; #5553 patched that symptom but the core approach can't close W6). Removing it cleans the dead + risky auto-call path off `main`. The real root — the class-capture materialization mis-boxing the pointer (the scale-emergent captured-pointer mis-box class, CLAUDE.md "captured pointer values must be NaN-boxed before storing") — is tracked under #5437 for a dedicated fix at the capture-store layer.
+
 ## v0.5.1201 — fix(runtime): #5437 — CJS-interop probe on a module-default wrapper must not auto-call it (boot-crash fix for #5546)
 
 Follow-up to #5546. That change registers CJS module-default wrapper closures and, on a property miss, auto-calls the wrapper (`js_closure_call0`) to obtain `module.exports`. But for a CJS module whose `module.exports` **is a function** (e.g. `debug` → `createDebug`), the wrapper *is* that function, and the ubiquitous `_interop_require_default(require("debug"))` interop reads `.__esModule` off it → property miss → the fallback **called the module's function with no args** as a side effect → e.g. `enabled(undefined)` → `undefined.length` → threw at module-init (server exits at boot). This regressed the Next.js bundle from serving (HTTP 500) to crashing at boot (HTTP 000) and could break other SWC/Babel-compiled-CJS programs.
diff --git a/CLAUDE.md b/CLAUDE.md
index e7fb81880e..c678337bf5 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:** 0.5.1201
+**Current Version:** 0.5.1202
 
 
 ## TypeScript Parity Status
diff --git a/Cargo.lock b/Cargo.lock
index 05a3c84dfb..a7a29ea324 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5325,7 +5325,7 @@ checksum = "9b4f627cb1b25917193a259e49bdad08f671f8d9708acfd5fe0a8c1455d87220"
 
 [[package]]
 name = "perry"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "base64",
@@ -5382,14 +5382,14 @@ dependencies = [
 
 [[package]]
 name = "perry-api-manifest"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "serde",
 ]
 
 [[package]]
 name = "perry-audio-miniaudio"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "cc",
  "libc",
@@ -5397,7 +5397,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "log",
@@ -5412,7 +5412,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-arkts"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5421,7 +5421,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-glance"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5429,7 +5429,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-js"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-dispatch",
@@ -5439,7 +5439,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-swiftui"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5448,7 +5448,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wasm"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "base64",
@@ -5461,7 +5461,7 @@ dependencies = [
 
 [[package]]
 name = "perry-codegen-wear-tiles"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -5469,7 +5469,7 @@ dependencies = [
 
 [[package]]
 name = "perry-container-compose"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -5498,14 +5498,14 @@ dependencies = [
 
 [[package]]
 name = "perry-container-e2e"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
 ]
 
 [[package]]
 name = "perry-diagnostics"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "serde",
  "serde_json",
@@ -5513,7 +5513,7 @@ dependencies = [
 
 [[package]]
 name = "perry-dispatch"
-version = "0.5.1201"
+version = "0.5.1202"
 
 [[package]]
 name = "perry-doc-fixture-my-bindings"
@@ -5524,7 +5524,7 @@ dependencies = [
 
 [[package]]
 name = "perry-doc-tests"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "clap",
@@ -5539,14 +5539,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ads"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-argon2"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "argon2",
  "perry-ffi",
@@ -5554,7 +5554,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-axios"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "reqwest",
@@ -5563,7 +5563,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-bcrypt"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "bcrypt",
  "perry-ffi",
@@ -5571,7 +5571,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-better-sqlite3"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "rusqlite",
@@ -5579,7 +5579,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cheerio"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "scraper",
@@ -5587,7 +5587,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-commander"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5595,7 +5595,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-cron"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "chrono",
  "cron 0.16.0",
@@ -5605,7 +5605,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dayjs"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5613,7 +5613,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-decimal"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "rust_decimal",
@@ -5621,7 +5621,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-dotenv"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "serde_json",
@@ -5629,7 +5629,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ethers"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "rand 0.8.6",
@@ -5637,7 +5637,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-events"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5645,14 +5645,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-exponential-backoff"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-fastify"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "bytes",
  "http-body-util",
@@ -5669,7 +5669,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-fetch"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5681,7 +5681,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "bytes",
  "lazy_static",
@@ -5695,7 +5695,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-http-server"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "bytes",
  "h2",
@@ -5718,7 +5718,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ioredis"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5728,7 +5728,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-jsonwebtoken"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "jsonwebtoken",
@@ -5739,7 +5739,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-lru-cache"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "lru",
  "perry-ffi",
@@ -5747,7 +5747,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-moment"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5755,7 +5755,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mongodb"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "bson",
  "futures-util",
@@ -5767,7 +5767,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-mysql2"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "chrono",
  "perry-ffi",
@@ -5777,7 +5777,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nanoid"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "nanoid",
  "perry-ffi",
@@ -5786,7 +5786,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-net"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "perry-runtime",
@@ -5798,7 +5798,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-nodemailer"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "lettre",
  "perry-ffi",
@@ -5808,7 +5808,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pdf"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "printpdf",
@@ -5816,7 +5816,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-pg"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "sqlx",
@@ -5825,7 +5825,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ratelimit"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "governor",
  "perry-ffi",
@@ -5833,7 +5833,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-sharp"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "fast_image_resize",
  "image",
@@ -5843,14 +5843,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-slugify"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
 ]
 
 [[package]]
 name = "perry-ext-streams"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "lazy_static",
  "perry-ffi",
@@ -5859,7 +5859,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-uuid"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "uuid",
@@ -5867,7 +5867,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-validator"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ffi",
  "regex",
@@ -5877,7 +5877,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-ws"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "futures-util",
  "lazy_static",
@@ -5889,7 +5889,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ext-zlib"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "brotli",
  "flate2",
@@ -5898,7 +5898,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ffi"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "dashmap",
  "once_cell",
@@ -5907,7 +5907,7 @@ dependencies = [
 
 [[package]]
 name = "perry-hir"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-api-manifest",
@@ -5925,7 +5925,7 @@ dependencies = [
 
 [[package]]
 name = "perry-parser"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-diagnostics",
@@ -5937,7 +5937,7 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "base64",
@@ -5970,14 +5970,14 @@ dependencies = [
 
 [[package]]
 name = "perry-runtime-static"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-runtime",
 ]
 
 [[package]]
 name = "perry-stdlib"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "aes 0.8.4",
  "aes-gcm",
@@ -6069,14 +6069,14 @@ dependencies = [
 
 [[package]]
 name = "perry-stdlib-static"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-stdlib",
 ]
 
 [[package]]
 name = "perry-transform"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "perry-hir",
@@ -6086,7 +6086,7 @@ dependencies = [
 
 [[package]]
 name = "perry-types"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "anyhow",
  "thiserror 1.0.69",
@@ -6094,14 +6094,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ui-model",
 ]
 
 [[package]]
 name = "perry-ui-android"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "itoa",
@@ -6118,7 +6118,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-geisterhand"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "rand 0.8.6",
  "serde",
@@ -6128,7 +6128,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-gtk4"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "cairo-rs",
@@ -6151,7 +6151,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-ios"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "block2",
@@ -6167,7 +6167,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-macos"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "block2",
@@ -6182,7 +6182,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-model"
-version = "0.5.1201"
+version = "0.5.1202"
 
 [[package]]
 name = "perry-ui-test"
@@ -6190,11 +6190,11 @@ version = "0.1.0"
 
 [[package]]
 name = "perry-ui-testkit"
-version = "0.5.1201"
+version = "0.5.1202"
 
 [[package]]
 name = "perry-ui-tvos"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "block2",
@@ -6210,7 +6210,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-visionos"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "block2",
@@ -6226,7 +6226,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-watchos"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "block2",
  "libc",
@@ -6239,7 +6239,7 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "libc",
@@ -6256,14 +6256,14 @@ dependencies = [
 
 [[package]]
 name = "perry-ui-windows-winui"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "perry-ui-windows",
 ]
 
 [[package]]
 name = "perry-updater"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "base64",
  "ed25519-dalek",
@@ -6277,7 +6277,7 @@ dependencies = [
 
 [[package]]
 name = "perry-wasm-host"
-version = "0.5.1201"
+version = "0.5.1202"
 dependencies = [
  "wasmi",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 9bdeee23fc..f7c9d711cf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -301,7 +301,7 @@ strip = false
 codegen-units = 16
 
 [workspace.package]
-version = "0.5.1201"
+version = "0.5.1202"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/PerryTS/perry"
diff --git a/crates/perry-codegen/src/expr/new_dynamic.rs b/crates/perry-codegen/src/expr/new_dynamic.rs
index 37e8af4a43..f88a771ee5 100644
--- a/crates/perry-codegen/src/expr/new_dynamic.rs
+++ b/crates/perry-codegen/src/expr/new_dynamic.rs
@@ -212,8 +212,16 @@ pub(crate) fn lower(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
             }
 
             // Case 1 + 2: callee is statically a class.
+            //
+            // #5437: this is a NewDynamic-routed construct (`new (Foo)()`,
+            // `new ns.Foo()` for a namespace import) — the bare-`ast::Expr::Ident`
+            // HIR arm that appends class captures was NOT taken, so the captures
+            // are absent from `args`. Route to `lower_new_member_captured` so a
+            // function-nested capturing class fills its `__perry_cap_*` ctor
+            // params from the decl-site snapshot. No-op for non-capturing
+            // classes (no cap params to fill).
             if let Some(name) = try_static_class_name(callee.as_ref(), ctx) {
-                return lower_new(ctx, name, args);
+                return crate::lower_call::lower_new_member_captured(ctx, name, args);
             }
 
             // date-fns `constructFrom(date, value)`:
@@ -511,6 +519,13 @@ pub(crate) fn lower(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
             // when it sees the original literal — read it back here and
             // dispatch to `lower_new` instead of the empty-object
             // fallback.
+            //
+            // #5437: this is a MEMBER-callee construct — the class's
+            // captures are NOT appended at this `new` site (the captured
+            // enclosing local is out of scope here), so route to
+            // `lower_new_member_captured` which fills the synthesized
+            // `__perry_cap_*` ctor params from the class's decl-site capture
+            // snapshot instead of binding them to `undefined`.
             if let Expr::PropertyGet { object, property } = callee.as_ref() {
                 if let Expr::LocalGet(obj_id) = object.as_ref() {
                     if let Some(class_name) = ctx
@@ -519,7 +534,11 @@ pub(crate) fn lower(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
                         .and_then(|f| f.get(property))
                         .cloned()
                     {
-                        return lower_new(ctx, &class_name, args);
+                        return crate::lower_call::lower_new_member_captured(
+                            ctx,
+                            &class_name,
+                            args,
+                        );
                     }
                 }
             }
diff --git a/crates/perry-codegen/src/expr/this_super_call.rs b/crates/perry-codegen/src/expr/this_super_call.rs
index 99d4b71fb8..41255ba7e8 100644
--- a/crates/perry-codegen/src/expr/this_super_call.rs
+++ b/crates/perry-codegen/src/expr/this_super_call.rs
@@ -771,8 +771,28 @@ pub(crate) fn lower(ctx: &mut FnCtx<'_>, expr: &Expr) -> Result<String> {
                         }));
                     }
                 }
-                let saved_scope =
-                    bind_inline_constructor_params(ctx, &parent_ctor.params, &lowered_args);
+                // #5437: fill the parent's cap params from its decl-site
+                // capture snapshot. The snapshot is authoritative for EVERY
+                // parent cap param — `bind_inline_constructor_params` consumes
+                // the values the child-forwarding loop appended above only to
+                // keep the user/cap tail-split aligned, then discards them in
+                // favour of `js_class_capture_value`. This matters when the
+                // captured local is out of scope at the super-call site (the
+                // forwarded value would be `undefined`); the snapshot still
+                // holds the correct decl-site capture. `backfill` sets
+                // `caps_absent_from_args=false` because the caps ARE present in
+                // `lowered_args` (this is not the caps-absent member-new path).
+                let parent_capture_fill = ctx
+                    .class_ids
+                    .get(effective_parent_name.as_str())
+                    .copied()
+                    .map(crate::lower_call::CaptureFill::backfill);
+                let saved_scope = bind_inline_constructor_params(
+                    ctx,
+                    &parent_ctor.params,
+                    &lowered_args,
+                    parent_capture_fill,
+                );
 
                 ctx.class_stack.push(effective_parent_name.clone());
                 crate::stmt::lower_stmts(ctx, &parent_ctor.body)?;
diff --git a/crates/perry-codegen/src/lower_call/mod.rs b/crates/perry-codegen/src/lower_call/mod.rs
index 24e7b1f1a3..8a810f0a4c 100644
--- a/crates/perry-codegen/src/lower_call/mod.rs
+++ b/crates/perry-codegen/src/lower_call/mod.rs
@@ -102,7 +102,10 @@ pub(crate) use native::lower_native_method_call;
 // (codegen.rs / expr.rs / stmt.rs) so `crate::lower_call::lower_new`
 // etc. keep resolving after the split.
 pub(crate) use field_init::{apply_field_initializers_recursive, FieldInitMode};
-pub(crate) use new::{bind_inline_constructor_params, lower_new, restore_inline_constructor_scope};
+pub(crate) use new::{
+    bind_inline_constructor_params, lower_new, lower_new_member_captured,
+    restore_inline_constructor_scope, CaptureFill,
+};
 // The derived-ctor no-super static-throw predicates (shared with the
 // standalone-ctor-symbol path in `codegen/method.rs`, which is the default
 // `new` lowering when `force_ctor_call` redirects construction to the shared
diff --git a/crates/perry-codegen/src/lower_call/new.rs b/crates/perry-codegen/src/lower_call/new.rs
index 3e8daa4624..d392cc3060 100644
--- a/crates/perry-codegen/src/lower_call/new.rs
+++ b/crates/perry-codegen/src/lower_call/new.rs
@@ -35,6 +35,7 @@ pub(crate) fn bind_inline_constructor_params(
     ctx: &mut FnCtx<'_>,
     params: &[Param],
     lowered_args: &[String],
+    capture_fill: Option<CaptureFill>,
 ) -> InlineConstructorScope {
     let saved = InlineConstructorScope {
         locals: ctx.locals.clone(),
@@ -43,7 +44,8 @@ pub(crate) fn bind_inline_constructor_params(
     };
 
     crate::codegen::arguments::add_arguments_mapped_boxes(params, &mut ctx.boxed_vars);
-    let values = inline_constructor_param_values(ctx, params, lowered_args);
+    let values =
+        inline_constructor_param_values_with_class(ctx, params, lowered_args, capture_fill);
     for (param, arg_val) in params.iter().zip(values.iter()) {
         let slot = ctx.func.alloca_entry(DOUBLE);
         if ctx.boxed_vars.contains(&param.id) && param.arguments_object.is_none() {
@@ -70,6 +72,62 @@ fn inline_constructor_param_values(
     ctx: &mut FnCtx<'_>,
     params: &[Param],
     lowered_args: &[String],
+) -> Vec<String> {
+    inline_constructor_param_values_with_class(ctx, params, lowered_args, None)
+}
+
+/// Where a synthesized `__perry_cap_<id>` param's value comes from when the
+/// `new` site did not supply it as an appended arg.
+#[derive(Clone, Copy)]
+pub(crate) struct CaptureFill {
+    /// The constructing class's id, used to read its DECL-SITE capture
+    /// snapshot (`js_class_capture_value(cid, slot)`).
+    cid: u32,
+    /// `true` when `lowered_args` does NOT contain appended cap values — the
+    /// member-callee `new ns.C(...)` path. Then ALL `lowered_args` are user
+    /// args and EVERY cap param fills from the snapshot. `false` for the
+    /// bare-identifier `new C(...)` path, where the HIR appended the caps as
+    /// trailing args (tail-split keeps binding them); the snapshot then only
+    /// backfills a cap the HIR didn't append.
+    caps_absent_from_args: bool,
+}
+
+impl CaptureFill {
+    /// Snapshot-only BACKFILL for a cap param the caller's args did not
+    /// supply: the `lowered_args` still carry their appended cap values
+    /// (tail-split keeps binding them). Used by the `super(...)` inline path,
+    /// which explicitly forwards parent caps as args.
+    pub(crate) fn backfill(cid: u32) -> Self {
+        CaptureFill {
+            cid,
+            caps_absent_from_args: false,
+        }
+    }
+}
+
+/// As [`inline_constructor_param_values`], but fills a synthesized
+/// `__perry_cap_<id>` param that the `new` site did not supply from the
+/// class's DECL-SITE capture snapshot (`js_class_capture_value(cid, slot)`)
+/// instead of `undefined`.
+///
+/// #5437 (W6): a member-callee construct `new ns.C()` of a function-nested
+/// class that captured an enclosing local is statically routed to
+/// `lower_new("C", [])` (the `#740` object-field-alias arm in
+/// `expr/new_dynamic.rs`) — the captures are NOT appended as trailing args
+/// (that only happens for the bare-identifier `new C()` HIR arm). With no
+/// cap args the cap params bound to `undefined` and every method reading a
+/// captured local saw `undefined`. The bare-`new C()` HIR-append cannot be
+/// reused for `new ns.C()`: at the outer (member) `new` site the captured
+/// enclosing local is OUT OF SCOPE, so `LocalGet(cid)` would itself read
+/// `undefined`. The decl-site snapshot (registered at the class's
+/// declaration by `js_class_register_capture_values`) holds the correct
+/// captured values. `fill = None` keeps the prior `undefined` fill (no
+/// behavior change for non-capturing/unknown classes).
+fn inline_constructor_param_values_with_class(
+    ctx: &mut FnCtx<'_>,
+    params: &[Param],
+    lowered_args: &[String],
+    capture_fill: Option<CaptureFill>,
 ) -> Vec<String> {
     let undef = double_literal(f64::from_bits(crate::nanbox::TAG_UNDEFINED));
     // Synthesized `__perry_cap_<id>` capture params are always TRAILING
@@ -80,25 +138,70 @@ fn inline_constructor_param_values(
     // bundle), so positional binding put the user arg into the capture
     // slot. Bind capture params from the args TAIL and user params from
     // the head.
-    let n_caps = params
-        .iter()
-        .filter(|p| {
-            p.name.starts_with("__perry_cap_") && !p.is_rest && p.arguments_object.is_none()
+    //
+    // #5437: when a decl-site snapshot is available (`capture_fill = Some`),
+    // EVERY synthesized cap param is filled from that snapshot — the
+    // authoritative decl-site capture value — regardless of whether the `new`
+    // site appended cap args. This is what closes W6: the bundle's bare-`new
+    // uS(...)` appends a MIS-BOXED `uw` cap (the multi-level capture chain
+    // materialized the wrong value), while `uS`'s decl-site snapshot holds the
+    // correct module-exports object; preferring the snapshot makes
+    // `new uw.SharedCacheControls` resolve.
+    //
+    // The split between user args and the (now ignored) appended cap args
+    // still matters for the USER params:
+    //   - member-callee `new ns.C(...)`: caps are NOT appended, so ALL
+    //     `lowered_args` are user args → `n_caps = 0`. (`new ns.C("ARG")`
+    //     binds the user param to `"ARG"`, the cap to the snapshot.)
+    //   - bare-identifier `new C(...)`: the HIR appended the caps as trailing
+    //     args, so strip them (tail-split) to recover the leading user args;
+    //     the stripped cap values are discarded in favour of the snapshot.
+    let caps_absent = matches!(
+        capture_fill,
+        Some(CaptureFill {
+            caps_absent_from_args: true,
+            ..
         })
-        .count()
-        .min(lowered_args.len());
+    );
+    let n_caps = if caps_absent {
+        0
+    } else {
+        params
+            .iter()
+            .filter(|p| {
+                p.name.starts_with("__perry_cap_") && !p.is_rest && p.arguments_object.is_none()
+            })
+            .count()
+            .min(lowered_args.len())
+    };
     let user_len = lowered_args.len() - n_caps;
     let (user_args, cap_args) = lowered_args.split_at(user_len);
     let mut cap_iter = cap_args.iter();
 
     let mut out = Vec::with_capacity(params.len());
     let mut visible_index = 0usize;
+    // The cap-slot index of the NEXT cap param: the index of the value in
+    // the decl-site snapshot (registered in `captures_vec` / cap-param
+    // declaration order, which is the same order they appear here).
+    let mut cap_slot = 0u32;
     for param in params {
         if param.name.starts_with("__perry_cap_")
             && !param.is_rest
             && param.arguments_object.is_none()
         {
-            out.push(cap_iter.next().cloned().unwrap_or_else(|| undef.clone()));
+            let slot = cap_slot;
+            cap_slot += 1;
+            // Consume (and discard) any appended cap arg so the tail stays
+            // aligned, then fill from the snapshot when one is registered.
+            let appended = cap_iter.next();
+            out.push(match capture_fill {
+                Some(CaptureFill { cid, .. }) => ctx.block().call(
+                    DOUBLE,
+                    "js_class_capture_value",
+                    &[(I32, &cid.to_string()), (I32, &slot.to_string())],
+                ),
+                None => appended.cloned().unwrap_or_else(|| undef.clone()),
+            });
         } else if param.arguments_object.is_some() {
             out.push(pack_lowered_args_array(ctx, user_args));
         } else if param.is_rest {
@@ -228,6 +331,7 @@ fn call_local_constructor_symbol(
     class: &perry_hir::Class,
     obj_box: &str,
     lowered_args: &[String],
+    caps_absent_from_args: bool,
 ) -> Option<String> {
     let ctor_method_name = format!("{}_constructor", class.name);
     let ctor_name = ctx
@@ -275,8 +379,16 @@ fn call_local_constructor_symbol(
         }
         found
     };
+    let capture_fill = ctx
+        .class_ids
+        .get(&class.name)
+        .copied()
+        .map(|cid| CaptureFill {
+            cid,
+            caps_absent_from_args,
+        });
     let mut ctor_values = if let Some(params) = effective_params {
-        inline_constructor_param_values(ctx, &params, lowered_args)
+        inline_constructor_param_values_with_class(ctx, &params, lowered_args, capture_fill)
     } else {
         lowered_args.to_vec()
     };
@@ -315,6 +427,30 @@ fn call_local_constructor_symbol(
 ///   enclosing function, not the constructor body)
 /// - No method dispatch or vtables — those land in Phase C.2/C.3
 pub(crate) fn lower_new(ctx: &mut FnCtx<'_>, class_name: &str, args: &[Expr]) -> Result<String> {
+    // Bare-identifier `new C(...)` path: the HIR `Expr::New` arm appended the
+    // class captures as trailing `LocalGet` args, so caps are PRESENT in
+    // `args`.
+    lower_new_impl(ctx, class_name, args, false)
+}
+
+/// Member-callee `new ns.C(...)` construct (#5437): the captures were NOT
+/// appended at the `new` site (the captured enclosing local is out of scope
+/// there), so every synthesized `__perry_cap_*` ctor param fills from the
+/// class's decl-site capture snapshot instead. All of `args` are USER args.
+pub(crate) fn lower_new_member_captured(
+    ctx: &mut FnCtx<'_>,
+    class_name: &str,
+    args: &[Expr],
+) -> Result<String> {
+    lower_new_impl(ctx, class_name, args, true)
+}
+
+fn lower_new_impl(
+    ctx: &mut FnCtx<'_>,
+    class_name: &str,
+    args: &[Expr],
+    caps_absent_from_args: bool,
+) -> Result<String> {
     // Built-in Web classes that the runtime provides constructors for.
     // These are checked BEFORE the ctx.classes lookup because the user
     // code may shadow the name — if they do, the class lookup below
@@ -929,7 +1065,13 @@ pub(crate) fn lower_new(ctx: &mut FnCtx<'_>, class_name: &str, args: &[Expr]) ->
         // function ("value is not a function" on `new Chalk(...).red(...)`).
         // `js_ctor_return_override` returns `obj_box` for an `undefined`/
         // primitive (base) return, so ordinary ctors are unaffected.
-        if let Some(ctor_ret) = call_local_constructor_symbol(ctx, class, &obj_box, &lowered_args) {
+        if let Some(ctor_ret) = call_local_constructor_symbol(
+            ctx,
+            class,
+            &obj_box,
+            &lowered_args,
+            caps_absent_from_args,
+        ) {
             let is_derived = class.extends.is_some()
                 || class.extends_name.is_some()
                 || class.native_extends.is_some()
@@ -1077,10 +1219,17 @@ pub(crate) fn lower_new(ctx: &mut FnCtx<'_>, class_name: &str, args: &[Expr]) ->
     // `LocalGet` codegen doesn't return 0.0. Locals/local_types are
     // saved-and-restored around the whole inlined ctor flow below; we
     // mirror that here so the ctor params don't leak out of `new`.
-    let mut saved_scope_for_ctor = class
-        .constructor
-        .as_ref()
-        .map(|ctor| bind_inline_constructor_params(ctx, &ctor.params, &lowered_args));
+    let ctor_capture_fill = ctx
+        .class_ids
+        .get(class_name)
+        .copied()
+        .map(|cid| CaptureFill {
+            cid,
+            caps_absent_from_args,
+        });
+    let mut saved_scope_for_ctor = class.constructor.as_ref().map(|ctor| {
+        bind_inline_constructor_params(ctx, &ctor.params, &lowered_args, ctor_capture_fill)
+    });
 
     if let Some(stop_at) = inherited_ctor_class.clone() {
         apply_field_initializers_recursive(ctx, class_name, FieldInitMode::UpToInclusive(stop_at))?;
@@ -1144,8 +1293,19 @@ pub(crate) fn lower_new(ctx: &mut FnCtx<'_>, class_name: &str, args: &[Expr]) ->
         while let Some(pname) = parent_name {
             if let Some(parent_class) = ctx.classes.get(pname).copied() {
                 if let Some(parent_ctor) = &parent_class.constructor {
-                    let saved_scope =
-                        bind_inline_constructor_params(ctx, &parent_ctor.params, &lowered_args);
+                    // #5437: fill any unfilled parent cap param from the
+                    // parent's decl-site capture snapshot.
+                    let parent_capture_fill =
+                        ctx.class_ids.get(pname).copied().map(|cid| CaptureFill {
+                            cid,
+                            caps_absent_from_args,
+                        });
+                    let saved_scope = bind_inline_constructor_params(
+                        ctx,
+                        &parent_ctor.params,
+                        &lowered_args,
+                        parent_capture_fill,
+                    );
 
                     // Push the parent class name so `this` inside the
                     // parent ctor body resolves field names via the
diff --git a/crates/perry/tests/issue_5437_member_new_captured_class.rs b/crates/perry/tests/issue_5437_member_new_captured_class.rs
new file mode 100644
index 0000000000..4f7e298559
--- /dev/null
+++ b/crates/perry/tests/issue_5437_member_new_captured_class.rs
@@ -0,0 +1,140 @@
+//! Regression test for #5437 (W6): a member-callee construct
+//! `new ns.C()` of a function-nested class that captured an enclosing-scope
+//! local DROPPED the captures, so every method that read a captured local
+//! saw `undefined`.
+//!
+//! Root: the bare-identifier `new C()` HIR arm appends the class captures as
+//! trailing `LocalGet(cid)` args, but the member-callee form
+//! (`new ns.C()`, where `ns` is an object literal whose field was a class
+//! expression) is statically routed by codegen's `#740` object-field-alias
+//! arm to `lower_new("C", [])` with NO captures appended. The synthesized
+//! `__perry_cap_*` ctor params then bound to `undefined`. The
+//! `LocalGet(cid)` append cannot be reused at the outer (member) `new`
+//! site — the captured enclosing local is out of scope there — so the fix
+//! fills the cap params from the class's DECL-SITE capture snapshot
+//! (`js_class_capture_value(cid, slot)`, registered at the class declaration
+//! by `js_class_register_capture_values`).
+//!
+//! Exercises (all member-new of a captured class):
+//!   - single object capture, no own ctor
+//!   - inheritance (sub + base both capturing)
+//!   - multiple captures (object + closure + string) + inheritance
+//!   - a USER ctor taking args alongside the captures (the user arg must NOT
+//!     be mis-split into the capture slot)
+//!   - a class declared in a NESTED function capturing two scopes' locals
+//!
+//! No `node_modules` dependency — the shapes are inline so it runs in CI.
+
+use std::path::PathBuf;
+use std::process::Command;
+
+fn perry_bin() -> PathBuf {
+    PathBuf::from(env!("CARGO_BIN_EXE_perry"))
+}
+
+#[test]
+fn member_new_of_captured_class_fills_captures_from_snapshot() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let entry = dir.path().join("main.ts");
+    let output = dir.path().join("main_bin");
+
+    std::fs::write(
+        &entry,
+        r#"
+// Class names are unique per case (distinct classes in one module) so the
+// shapes are isolated from one another.
+
+// 1. single object capture, no own ctor, member-new.
+function mkMin() {
+  const o = { m: "OK" };
+  class CMin { r() { return o.m; } }
+  return { CMin };
+}
+const nsMin = mkMin();
+console.log("1=" + new nsMin.CMin().r());
+
+// 2. inheritance: sub + base both capture, member-new of the sub.
+function mkInherit() {
+  const o = { m: "OBJ" };
+  class BaseInh { ro() { return o.m; } }
+  class SubInh extends BaseInh { rs() { return o.m + "!"; } }
+  return { BaseInh, SubInh };
+}
+const nsInh = mkInherit();
+const sInh = new nsInh.SubInh();
+console.log("2=" + sInh.ro() + "," + sInh.rs());
+
+// 3. multiple captures (object + closure + string) + inheritance.
+function mkMulti() {
+  const a = { x: "AX" };
+  const b = () => "BCLO";
+  const c = "CSTR";
+  class BaseMulti { ra() { return a.x; } rc() { return c; } }
+  class SubMulti extends BaseMulti { rb() { return b(); } ra2() { return a.x; } }
+  return { SubMulti };
+}
+const nsMulti = mkMulti();
+const sMulti = new nsMulti.SubMulti();
+console.log("3=" + sMulti.ra() + "," + sMulti.rb() + "," + sMulti.rc() + "," + sMulti.ra2());
+
+// 4. a USER ctor taking args alongside captures — the user arg must bind to
+// the user param and the capture must come from the snapshot (the tail-split
+// must NOT pull the lone user arg into the capture slot).
+function mkUserCtor() {
+  const cap = { k: "CAP" };
+  class CUser {
+    n: string;
+    constructor(n: string) { this.n = n; }
+    get() { return this.n + "/" + cap.k; }
+  }
+  return { CUser };
+}
+const nsUser = mkUserCtor();
+console.log("4=" + new nsUser.CUser("ARG").get());
+
+// 5. class declared in a NESTED function, capturing two scopes' locals.
+function outer() {
+  const tag = "OUTER";
+  function inner() {
+    const local = { v: "INNER" };
+    class CNest { both() { return tag + ":" + local.v; } }
+    return { CNest };
+  }
+  return inner();
+}
+const nsNest = outer();
+console.log("5=" + new nsNest.CNest().both());
+"#,
+    )
+    .expect("write entry");
+
+    let compile = Command::new(perry_bin())
+        .current_dir(dir.path())
+        .arg("compile")
+        .arg(&entry)
+        .arg("-o")
+        .arg(&output)
+        .output()
+        .expect("run perry compile");
+    assert!(
+        compile.status.success(),
+        "perry compile failed\nstdout:\n{}\nstderr:\n{}",
+        String::from_utf8_lossy(&compile.stdout),
+        String::from_utf8_lossy(&compile.stderr)
+    );
+
+    let run = Command::new(&output).output().expect("run compiled binary");
+    assert!(
+        run.status.success(),
+        "compiled binary failed\nstatus: {:?}\nstdout:\n{}\nstderr:\n{}",
+        run.status,
+        String::from_utf8_lossy(&run.stdout),
+        String::from_utf8_lossy(&run.stderr)
+    );
+    let stdout = String::from_utf8_lossy(&run.stdout);
+    assert_eq!(
+        stdout, "1=OK\n2=OBJ,OBJ!\n3=AX,BCLO,CSTR,AX\n4=ARG/CAP\n5=OUTER:INNER\n",
+        "member-new of a function-nested capturing class must fill the \
+         synthesized __perry_cap_* params from the decl-site snapshot (#5437)"
+    );
+}