diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index fbf7bb6fe21..99f05f3abec 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -64,6 +64,18 @@ jobs:
       - uses: actions/setup-python@v2
       - name: Install Dependencies
         run: sudo ./.github/workflows/posix-deps-apt.sh
+      - name: Add ccache to PATH
+        run: echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+      - name: Configure ccache action
+        uses: hendrikmuhs/ccache-action@v1
+      - name: Check Autoconf version 2.69 and aclocal 1.16.3
+        run: |
+          grep "Generated by GNU Autoconf 2.69" configure
+          grep "aclocal 1.16.3" aclocal.m4
+          grep -q "runstatedir" configure
+          grep -q "PKG_PROG_PKG_CONFIG" aclocal.m4
+      - name: Regenerate autoconf files
+        run: docker run --rm -v $(pwd):/src quay.io/tiran/cpython_autoconf:269
       - name: Build CPython
         run: |
           # Build Python with the libpython dynamic library
@@ -75,9 +87,10 @@ jobs:
           git add -u
           changes=$(git status --porcelain)
           # Check for changes in regenerated files
-          if ! test -z "$changes"
-          then
-            echo "Generated files not up to date. Perhaps you forgot to run make regen-all or build.bat --regen ;)"
+          if test -n "$changes"; then
+            echo "Generated files not up to date."
+            echo "Perhaps you forgot to run make regen-all or build.bat --regen. ;)"
+            echo "configure files must be regenerated with a specific, unpatched version of autoconf."
             echo "$changes"
             exit 1
           fi
@@ -85,10 +98,6 @@ jobs:
         run: make smelly
       - name: Check limited ABI symbols
         run: make check-limited-abi
-      - name: Check Autoconf version 2.69
-        run: |
-          grep "Generated by GNU Autoconf 2.69" configure
-          grep "PKG_PROG_PKG_CONFIG" aclocal.m4
 
   build_win32:
     name: 'Windows (x86)'
diff --git a/.gitignore b/.gitignore
index cfd3163cd18..39de8410200 100644
--- a/.gitignore
+++ b/.gitignore
@@ -115,6 +115,8 @@ Tools/unicode/data/
 /config.log
 /config.status
 /config.status.lineno
+# hendrikmuhs/ccache-action@v1
+/.ccache
 /platform
 /profile-clean-stamp
 /profile-run-stamp
diff --git a/Misc/NEWS.d/next/Build/2021-12-06-09-31-27.bpo-44035.BiO4XC.rst b/Misc/NEWS.d/next/Build/2021-12-06-09-31-27.bpo-44035.BiO4XC.rst
new file mode 100644
index 00000000000..7530587b73d
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2021-12-06-09-31-27.bpo-44035.BiO4XC.rst
@@ -0,0 +1,2 @@
+CI now verifies that autoconf files have been regenerated with a current and
+unpatched autoconf package.