diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index a0f619cb393..156da172ac7 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -8,6 +8,11 @@ concurrency:
     group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
     cancel-in-progress: true
 
+env:
+  CACHE_KEY_PART: >
+    ${{ ( github.event_name == 'pull_request' ) && github.base_ref
+     }}${{ ( github.event_name == 'pull_request' ) && '-' }}${{ github.head_ref }}
+  GITHUB_JSON: ${{ toJSON(github) }} # Helps in debugging Github Action
 # A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
   # This workflow contains a single job
@@ -41,8 +46,11 @@ jobs:
         uses: actions/cache/restore@v4
         with:
           path: ./.github/tmp
-          key: "phpstan-cache-${{ matrix.php-version }}-${{ github.run_id }}"
+          key: phpstan-cache-${{ matrix.php-version }}-${{ env.CACHE_KEY_PART }}-${{ github.run_id }}
           restore-keys: |
+            phpstan-cache-${{ matrix.php-version }}-${{ env.CACHE_KEY_PART }}-
+            phpstan-cache-${{ matrix.php-version }}-${{ github.head_ref }}-
+            phpstan-cache-${{ matrix.php-version }}-${{ github.base_ref }}-
             phpstan-cache-${{ matrix.php-version }}-
       - name: Show debug into
         run: cd ./.github/tmp && ls -al
@@ -59,4 +67,4 @@ jobs:
         if: ${{ success() || ( ! cancelled() && steps.cache.outputs.cache-hit != 'true' ) }}
         with:
           path: ./.github/tmp
-          key: "phpstan-cache-${{ matrix.php-version }}-${{ github.run_id }}"
+          key: phpstan-cache-${{ matrix.php-version }}-${{ env.CACHE_KEY_PART }}-${{ github.run_id }}