diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a1325562..e3db7fba 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -47,3 +47,18 @@ jobs:
       contents: read
       security-events: write
     uses: ./.github/workflows/codeql.yml
+
+  save_pr_number:
+    if: github.event_name != 'push'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Save PR number
+        env:
+          PR_NUMBER: ${{ github.event.number }}
+        run: |
+          echo $PR_NUMBER > pr_number.txt
+      - uses: actions/upload-artifact@v4
+        with:
+          name: pr_number
+          path: pr_number.txt
+          retention-days: 1
diff --git a/.github/workflows/cleanup-cache-postpr.yml b/.github/workflows/cleanup-cache-postpr.yml
new file mode 100644
index 00000000..5dc32a68
--- /dev/null
+++ b/.github/workflows/cleanup-cache-postpr.yml
@@ -0,0 +1,40 @@
+name: CleanUpCachePostPR
+
+on:
+  workflow_run:
+    workflows: [PostPR]
+    types:
+      - completed
+
+jobs:
+  CleanUpCcacheCachePostPR:
+    name: Clean Up Ccahe Cache Post PR
+    runs-on: ubuntu-latest
+    permissions:
+      actions: write
+      contents: read
+    env:
+      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Clean up ccahe
+        run: |
+          gh extension install actions/gh-actions-cache
+
+          REPO=${{ github.repository }}
+
+          gh run download ${{ github.event.workflow_run.id }} -n pr_number
+          pr_number=`cat pr_number.txt`
+          BRANCH=refs/pull/${pr_number}/merge
+
+          # Setting this to not fail the workflow while deleting cache keys.
+          set +e
+
+          keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH | cut -f 1)
+          # $keys might contain spaces. Thus we set IFS to \n.
+          IFS=$'\n'
+          for k in $keys
+          do
+            gh actions-cache delete "$k" -R $REPO -B $BRANCH --confirm
+          done
+          unset IFS
diff --git a/.github/workflows/cleanup-cache.yml b/.github/workflows/cleanup-cache.yml
index c0a4af9e..d1c49abc 100644
--- a/.github/workflows/cleanup-cache.yml
+++ b/.github/workflows/cleanup-cache.yml
@@ -17,7 +17,7 @@ jobs:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
       - uses: actions/checkout@v4
-      - name: Clean up ccache
+      - name: Clean up ccahe
         run: |
           gh extension install actions/gh-actions-cache
 
@@ -30,8 +30,8 @@ jobs:
           WORKFLOW_NAME="${{ github.event.workflow_run.name }}"
 
           if [[ $EVENT == "pull_request" ]]; then
-            pr_number=$(jq --raw-output .workflow_run.pull_requests[0].number < ${GITHUB_EVENT_PATH})
-            echo "Clean up cache for PR ${pr_number}."
+            gh run download ${{ github.event.workflow_run.id }} -n pr_number
+            pr_number=`cat pr_number.txt`
             BRANCH=refs/pull/${pr_number}/merge
           else
             BRANCH=refs/heads/${{ github.event.workflow_run.head_branch }}
@@ -54,7 +54,6 @@ jobs:
           IFS=$'\n'
           for j in $cached_jobs
           do
-            # Delete all entries except the last used one
             old_keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH --key "${j}-git-" --sort last-used | cut -f 1 | tail -n +2)
             for k in $old_keys
             do
diff --git a/.github/workflows/post-pr.yml b/.github/workflows/post-pr.yml
index 4155b6c5..2768ef37 100644
--- a/.github/workflows/post-pr.yml
+++ b/.github/workflows/post-pr.yml
@@ -5,35 +5,16 @@ on:
       - closed
 
 jobs:
-  cleanup_cache:
-    name: Clean Up Ccache Cache Post PR
+  cleanup:
     runs-on: ubuntu-latest
-    permissions:
-      actions: write
-      contents: read
-    env:
-      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@v4
-      - name: Clean up ccache
+      - name: Save PR number
+        env:
+          PR_NUMBER: ${{ github.event.number }}
         run: |
-          gh extension install actions/gh-actions-cache
-
-          REPO=${{ github.repository }}
-
-          pr_number=${{ github.event.number }}
-          echo "Clean up cache for PR ${pr_number}."
-          BRANCH=refs/pull/${pr_number}/merge
-
-          # Setting this to not fail the workflow while deleting cache keys.
-          set +e
-
-          # Delete all entries associated with this PR.
-          keys=$(gh actions-cache list -L 100 -R $REPO -B $BRANCH | cut -f 1)
-          # $keys might contain spaces. Thus we set IFS to \n.
-          IFS=$'\n'
-          for k in $keys
-          do
-            gh actions-cache delete "$k" -R $REPO -B $BRANCH --confirm
-          done
-          unset IFS
+          echo $PR_NUMBER > pr_number.txt
+      - uses: actions/upload-artifact@v4
+        with:
+          name: pr_number
+          path: pr_number.txt
+          retention-days: 1