diff --git a/.github/scripts/main/create-ocaml-cache.sh b/.github/scripts/main/create-ocaml-cache.sh
deleted file mode 100755
index 25b9bcdca94..00000000000
--- a/.github/scripts/main/create-ocaml-cache.sh
+++ /dev/null
@@ -1,42 +0,0 @@
-#!/bin/bash
-
-set -xue
-
-OCAML_BRANCH="$1"
-PREFIX="$2"
-EXE="$3"
-OCAML_LOCAL="$4"
-PLATFORM="$5"
-
-if [[ $OCAML_BRANCH -gt 407 ]]; then
-  make -C src_ext dune-local.stamp
-  cd src_ext/dune-local
-  ocaml boot/bootstrap.ml
-  cp _boot/dune.exe "$PREFIX/bin/dune$EXE"
-  cd ../..
-
-  git clean -dfX
-
-  if [[ -n $GITHUB_BASE_REF ]]; then
-    git tag combak
-    git fetch origin $GITHUB_BASE_REF
-    git checkout origin/$GITHUB_BASE_REF
-  fi
-
-  ./configure --with-vendored-deps
-  make
-  cp -a _build "$OCAML_LOCAL/"
-  rm -f "$OCAML_LOCAL/_build/log"
-  mv "$OCAML_LOCAL/_build/default/src_ext" "$OCAML_LOCAL/_build/"
-  rm -rf "$OCAML_LOCAL/_build/default"/* "$OCAML_LOCAL/_build/install"
-  mv "$OCAML_LOCAL/_build/src_ext" "$OCAML_LOCAL/_build/default/" 
-  git clean -dfX
-  if [[ -n $GITHUB_BASE_REF ]]; then
-    git checkout combak
-  fi
-fi
-
-# The Windows BSD tar can't cope with symlinks, so we pre-tar the archive and cache that!
-if [[ $PLATFORM = 'Windows' ]]; then
-  tar -C "$OCAML_LOCAL" -pcf "$OCAML_LOCAL.tar" .
-fi
diff --git a/.github/scripts/main/main.sh b/.github/scripts/main/main.sh
index bebd00bd96c..dcc5ccb8bda 100644
--- a/.github/scripts/main/main.sh
+++ b/.github/scripts/main/main.sh
@@ -28,10 +28,6 @@ case "$1" in
     CONFIGURE_PREFIX="$PREFIX";;
 esac
 
-if [ -e "$OCAML_LOCAL/_build" ]; then
-  cp -a "$OCAML_LOCAL/_build" .
-fi
-
 ./configure --prefix $CONFIGURE_PREFIX --with-vendored-deps --with-mccs
 if [ "$OPAM_TEST" != "1" ]; then
   echo 'DUNE_PROFILE=dev' >> Makefile.config
diff --git a/.github/scripts/main/ocaml-cache.sh b/.github/scripts/main/ocaml-cache.sh
index c9f578dc2cc..ac94f664775 100644
--- a/.github/scripts/main/ocaml-cache.sh
+++ b/.github/scripts/main/ocaml-cache.sh
@@ -146,8 +146,10 @@ EOF
   chmod +x "$OCAML_LOCAL/bin/ocamldoc"
 fi
 
-# Hand-over control to a separate script in case the branch being tested
-# updates this script, which will fail on Windows (since the script is "open"
-# and can't be overwritten)
-cp -pf .github/scripts/main/create-ocaml-cache.sh ../create-ocaml-cache.sh
-exec ../create-ocaml-cache.sh "$OCAML_BRANCH" "$PREFIX" "$EXE" "$OCAML_LOCAL" "$PLATFORM"
+make -C src_ext dune-local.stamp
+cd src_ext/dune-local
+ocaml boot/bootstrap.ml
+cp _boot/dune.exe "$PREFIX/bin/dune$EXE"
+cd ../..
+
+git clean -dfX
diff --git a/.github/workflows/ci.ml b/.github/workflows/ci.ml
index 6f753cebb8b..1d3fe06d38e 100644
--- a/.github/workflows/ci.ml
+++ b/.github/workflows/ci.ml
@@ -492,7 +492,7 @@ let main oc : unit =
   ] in
   let keys = [
     ("archives", "archives-1-${{ hashFiles('src_ext/Makefile.dune', 'src_ext/Makefile.sources', 'src_ext/Makefile', '.github/scripts/common/preamble.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/archives-cache.sh') }}-${{ env.OPAM_REPO_SHA }}");
-    ("ocaml-cache", "${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/create-ocaml-cache.sh') }}");
+    ("ocaml-cache", "${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh') }}");
     ("cygwin", "${{ hashFiles('.github/scripts/cygwin.cmd') }}-${{ env.CYGWIN_EPOCH }}");
     ("opam-bs-cache", "${{ hashFiles('.github/scripts/main/opam-bs-cache.sh', '*.opam', '.github/scripts/main/preamble.sh') }}");
   ] in
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 155edebc0e4..38a4f615181 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -58,8 +58,8 @@ jobs:
       run: |
         echo archives=archives-1-${{ hashFiles('src_ext/Makefile.dune', 'src_ext/Makefile.sources', 'src_ext/Makefile', '.github/scripts/common/preamble.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/archives-cache.sh') }}-${{ env.OPAM_REPO_SHA }}
         echo archives=archives-1-${{ hashFiles('src_ext/Makefile.dune', 'src_ext/Makefile.sources', 'src_ext/Makefile', '.github/scripts/common/preamble.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/archives-cache.sh') }}-${{ env.OPAM_REPO_SHA }} >> $GITHUB_OUTPUT
-        echo ocaml-cache=${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/create-ocaml-cache.sh') }}
-        echo ocaml-cache=${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh', '.github/scripts/main/create-ocaml-cache.sh') }} >> $GITHUB_OUTPUT
+        echo ocaml-cache=${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh') }}
+        echo ocaml-cache=${{ hashFiles('src_ext/Makefile.dune', '.github/scripts/main/ocaml-cache.sh', '.github/scripts/main/preamble.sh') }} >> $GITHUB_OUTPUT
         echo cygwin=${{ hashFiles('.github/scripts/cygwin.cmd') }}-${{ env.CYGWIN_EPOCH }}
         echo cygwin=${{ hashFiles('.github/scripts/cygwin.cmd') }}-${{ env.CYGWIN_EPOCH }} >> $GITHUB_OUTPUT
         echo opam-bs-cache=${{ hashFiles('.github/scripts/main/opam-bs-cache.sh', '*.opam', '.github/scripts/main/preamble.sh') }}