diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index db26ab66f..1dc995588 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -28,11 +28,14 @@ jobs:
       - name: Pin OASIS
         run: opam pin add oasis https://github.com/BinaryAnalysisPlatform/oasis.git
 
+      - name: Install system dependencies
+        run: opam depext -u bap-extra
+
       - name: Pin BAP
         run: opam pin add bap . --no-action
 
-      - name: Install system dependencies
-        run: opam depext -u bap-extra
+      - name: Install rest of the system dependencies
+        run: opam depext -u bap
 
       - name: Install Ghidra
         run: |
diff --git a/OMakefile b/OMakefile
index 89c04a1ca..1eff2f0a5 100644
--- a/OMakefile
+++ b/OMakefile
@@ -33,6 +33,7 @@ OCAMLFLAGS += -bin-annot               # (create .cmt/.cmti files)
 OCAMLFLAGS_ANNOT = -annot -bin-annot
 OCAMLFLAGS += $(OCAMLFLAGS_ANNOT)
 OCAMLFLAGS += -opaque
+OCAMLFLAGS += -w -6-16-58
 OCAMLOPTFLAGS += -O3
 
 # Until this point we allow to override variables via the command-line.
diff --git a/configure-omake b/configure-omake
index 9ee1aaedc..ce8e3c391 100755
--- a/configure-omake
+++ b/configure-omake
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+export OPAMCLI=2.0
+
 rm -f _oasis setup.log.om setup.data _oasis_setup.om
 mv oasis/benchmarks oasis/benchmarks.backup
 mv oasis/piqi-printers oasis/piqi-printers.backup
@@ -9,7 +11,7 @@ SECTIONS=`ocaml tools/oasis_sections.ml --sections --enable-everything`
 SETUPS=`ocaml tools/collect.ml setup.ml $SECTIONS`
 AB=`ocaml tools/collect.ml files.ab $SECTIONS`
 ocaml tools/cat.ml '"\n# $name\n"' -- $SECTIONS $AB _oasis
-ocaml tools/cat.ml '"\n#1 \"$name\"\n"' -- $SETUPS setup.ml.in setup.ml
+ocaml tools/cat.ml '"\n#1 \"$name\"\n"' -- setup.ml.pre.in $SETUPS setup.ml.in setup.ml
 cp oasis/common.backup oasis/common
 cp oasis/benchmarks.backup oasis/benchmarks
 cp oasis/piqi-printers.backup oasis/piqi-printers
diff --git a/lib/bap/bap_init_toplevel.ml b/lib/bap/bap_init_toplevel.ml
index 6d9a6592b..2b97472d8 100644
--- a/lib/bap/bap_init_toplevel.ml
+++ b/lib/bap/bap_init_toplevel.ml
@@ -3,6 +3,7 @@ open Bap_plugins.Std
 let install_printer printer =
   Topdirs.dir_install_printer Format.err_formatter
     (Longident.parse printer)
+[@@warning "-D"]
 
 let install_printers () =
   Core_kernel.Pretty_printer.all () |>
diff --git a/oasis/elf-loader b/oasis/elf-loader
index 3e73e51cd..b1bf032e7 100644
--- a/oasis/elf-loader
+++ b/oasis/elf-loader
@@ -7,7 +7,7 @@ Library elf
   Path:          lib/bap_elf
   Build$:        flag(everything) || flag(elf_loader)
   FindlibName:   bap-elf
-  BuildDepends:  bitstring, bitstring.ppx, regular, core_kernel, ppx_bap
+  BuildDepends:  bitstring, ppx_bitstring, regular, core_kernel, ppx_bap
   Modules: Bap_elf
   InternalModules:
                  Elf_parse,
diff --git a/opam/opam b/opam/opam
index 8fbc03a63..bbe56be4b 100644
--- a/opam/opam
+++ b/opam/opam
@@ -9,7 +9,7 @@ bug-reports: "https://github.com/BinaryAnalysisPlatform/bap/issues"
 depends: [
   "ocaml" {>= "4.07.0"}
   "base-unix"
-  "bitstring" {>= "3.0.0" & < "4.0.0"}
+  "ppx_bitstring" {>= "4.0.0"}
   "camlzip"
   "linenoise" {>= "1.1" & < "2.0"}
   "cmdliner" {>= "1.0" & < "2.0"}
diff --git a/plugins/mips/mips.ml b/plugins/mips/mips.ml
index d614c1dec..aba213f6e 100644
--- a/plugins/mips/mips.ml
+++ b/plugins/mips/mips.ml
@@ -101,7 +101,7 @@ let () =
       Hashtbl.find_and_call Std.delayed_opcodes name
         ~if_found:(fun delay ->
             KB.Value.put Insn.Slot.delay insn (Some delay))
-        ~if_not_found:(fun _ -> insn)
+        ~if_not_found:(fun _ -> Insn.empty)
     else !!Insn.empty in
   Bap_main.Extension.declare @@ fun _ctxt ->
   KB.Rule.(declare ~package:"mips" "delay-slot" |>