diff --git a/.github/workflows/assign-issues.yml b/.github/workflows/assign-issues.yml
index d5e34d3..e22725d 100644
--- a/.github/workflows/assign-issues.yml
+++ b/.github/workflows/assign-issues.yml
@@ -25,7 +25,7 @@ jobs:
       issues: write
     steps:
       - name: "Auto-assign issue"
-        uses: pozil/auto-assign-issue@v2
+        uses: pozil/auto-assign-issue@07fe6dc0e9771842b428f5739098d6140734e226 # v4.0.0
         with:
           assignees: fieryorc,shobsi,jiaxunwu,skarmarkar
           numOfAssignee: 1
diff --git a/.github/workflows/assign-prs.yml b/.github/workflows/assign-prs.yml
index c8d3f34..bad2c31 100644
--- a/.github/workflows/assign-prs.yml
+++ b/.github/workflows/assign-prs.yml
@@ -26,7 +26,7 @@ jobs:
       pull-requests: write
     steps:
       - name: "Auto-assign PR"
-        uses: pozil/auto-assign-issue@v2
+        uses: pozil/auto-assign-issue@07fe6dc0e9771842b428f5739098d6140734e226 # v4.0.0
         with:
           assignees: fieryorc,shobsi,jiaxunwu,skarmarkar
           numOfAssignee: 1