diff --git a/.github/actions/config-variations/action.yml b/.github/actions/config-variations/action.yml
index eb6d734b1c..75f6af1140 100644
--- a/.github/actions/config-variations/action.yml
+++ b/.github/actions/config-variations/action.yml
@@ -17,6 +17,11 @@ inputs:
 runs:
   using: 'composite'
   steps:
+    - name: "Validate test IDs"
+      shell: bash
+      run: |
+        ALLOWED="all pct-enabled pct-enabled-broken custom-zeroize native-cap-ON native-cap-OFF native-cap-ID_AA64PFR1_EL1 native-cap-CPUID_AVX2 no-asm serial-fips202 custom-randombytes custom-memcpy custom-memset custom-stdlib nblocks-1 nblocks-2 nblocks-4"
+        for t in ${{ inputs.tests }}; do echo "$ALLOWED" | grep -qw "$t" || { echo "Invalid test ID: $t. Allowed: $ALLOWED"; exit 1; }; done
     - name: "PCT enabled"
       if: ${{ inputs.tests == 'all' || contains(inputs.tests, 'pct-enabled') }}
       uses: ./.github/actions/multi-functest
diff --git a/.github/workflows/base.yml b/.github/workflows/base.yml
index b4ba224a5f..0106222511 100644
--- a/.github/workflows/base.yml
+++ b/.github/workflows/base.yml
@@ -186,7 +186,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        mingw-version: [5.4.0, 11.2.0, 12.2.0, 13.2.0, 14.2.0, 15.2.0]
+        # TODO: re-enable 5.4.0 or other old version
+        mingw-version: [11.2.0, 12.2.0, 13.2.0, 14.2.0, 15.2.0]
     name: Quickcheck (Mingw-w64 ${{ matrix.mingw-version }})
     runs-on: windows-latest
     steps:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 21ea226d0b..a5dc7d535c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -466,6 +466,7 @@ jobs:
         uses: ./.github/actions/config-variations
         with:
           gh_token: ${{ secrets.GITHUB_TOKEN }}
+          tests: 'pct-enabled invalid-test-id'
   check-cf-protections:
     name: Test control-flow protections  (${{ matrix.compiler.name }}, x86_64)
     strategy: