diff --git a/.github/workflows/generate-plantuml.yml b/.github/workflows/generate-plantuml.yml
index 67f805ef..1516c74b 100644
--- a/.github/workflows/generate-plantuml.yml
+++ b/.github/workflows/generate-plantuml.yml
@@ -25,7 +25,7 @@ jobs:
           args: -v -tsvg ${{steps.getfile.outputs.files}}
 
       - name: Push Local Changes
-        uses: stefanzweifel/git-auto-commit-action@v5.0.1
+        uses: stefanzweifel/git-auto-commit-action@b863ae1933cb653a53c021fe36dbb774e1fb9403 # v5.2.0
         with:
           commit_message: "Generate SVG files for PlantUML diagrams"
           branch: ${{ github.head_ref }}
diff --git a/.github/workflows/merge-schedule.yml b/.github/workflows/merge-schedule.yml
index ff7501b8..a83e7a43 100644
--- a/.github/workflows/merge-schedule.yml
+++ b/.github/workflows/merge-schedule.yml
@@ -16,7 +16,7 @@ jobs:
   merge_schedule:
     runs-on: ubuntu-latest
     steps:
-      - uses: gr2m/merge-schedule-action@v2
+      - uses: gr2m/merge-schedule-action@a9b6ddcf1282dfd66907bda8e7941dff59f03bad # v2.7.0
         with:
           # Merge method to use. Possible values are merge, squash or
           # rebase. Default is merge.