diff --git a/.github/scripts/audit_axioms.sh b/.github/scripts/audit_axioms.sh
index 9a5b08a..aaafe36 100755
--- a/.github/scripts/audit_axioms.sh
+++ b/.github/scripts/audit_axioms.sh
@@ -1,6 +1,16 @@
 #!/usr/bin/env bash
 set -euo pipefail
 root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+if (( $# > 1 )); then
+  echo "usage: $0 [lake-workspace]" >&2
+  exit 2
+fi
+workspace="${1:-$root}"
+if [[ ! -d "$workspace" ]]; then
+  echo "Lake workspace does not exist: $workspace" >&2
+  exit 2
+fi
+workspace="$(cd "$workspace" && pwd)"
 cd "$root"
 if command -v lake >/dev/null 2>&1; then
   lake_cmd="$(command -v lake)"
@@ -10,7 +20,9 @@ else
   echo "lake is not available" >&2
   exit 127
 fi
-if ! output="$($lake_cmd env lean .github/scripts/audit_axioms.lean 2>&1)"; then
+if ! output="$(
+  "$lake_cmd" -d="$workspace" env lean "$root/.github/scripts/audit_axioms.lean" 2>&1
+)"; then
   printf '%s\n' "$output" >&2
   exit 1
 fi
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index c4e1180..7e13037 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -73,6 +73,15 @@ jobs:
           use-mathlib-cache: true
           use-github-cache: false
 
+      - name: Restore CryptBoolean build cache
+        id: cryptboolean-cache
+        uses: actions/cache/restore@v6
+        with:
+          path: .lake/build
+          key: cryptboolean-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('lean-toolchain', 'lake-manifest.json', 'lakefile.lean', 'CryptBoolean.lean', 'CryptBoolean/**/*.lean') }}
+          restore-keys: |
+            cryptboolean-${{ runner.os }}-${{ runner.arch }}-
+
       - name: Build release library as a dependency
         env:
           GH_TOKEN: ${{ github.token }}
@@ -97,7 +106,15 @@ jobs:
       - name: Audit release proofs
         run: |
           ./.github/scripts/forbidden_tokens.sh
-          ./.github/scripts/audit_axioms.sh
+          ./.github/scripts/audit_axioms.sh \
+            "$RUNNER_TEMP/cryptboolean-release-builder"
+
+      - name: Save CryptBoolean build cache
+        if: steps.cryptboolean-cache.outputs.cache-hit != 'true'
+        uses: actions/cache/save@v6
+        with:
+          path: .lake/build
+          key: ${{ steps.cryptboolean-cache.outputs.cache-primary-key }}
 
       - name: Pack Lake release archive
         run: |