diff --git a/.github/workflows/flux-diff.yaml b/.github/workflows/flux-diff.yaml
index 3cf004c04c..4cc9c18be0 100644
--- a/.github/workflows/flux-diff.yaml
+++ b/.github/workflows/flux-diff.yaml
@@ -77,7 +77,7 @@ jobs:
           path: default
 
       - name: Diff Resources
-        uses: docker://ghcr.io/allenporter/flux-local:v4.3.1
+        uses: docker://ghcr.io/allenporter/flux-local:v4.3.1@sha256:b8cf9b8ff75b34a48dff58db5d8e4cd9cd6f0392025b98227d226fc84b75a379
         with:
           args: >-
             diff ${{ matrix.resources }}