diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 32839a2..bbb8910 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -216,7 +216,7 @@ jobs:
       # ─────────────────────────────────────────────────────────────────────────
       - name: Install cosign
         if: steps.vercheck.outputs.bumped == 'true' && steps.releasecheck.outputs.exists == 'false'
-        uses: sigstore/cosign-installer@398d4b0eeef1380460a10c8013a76f728fb906ac # v3
+        uses: sigstore/cosign-installer@6f9f17788090df1f26f669e9d70d6ae9567deba6 # v4.1.2
 
       - name: Sign release artifacts with cosign (keyless)
         if: steps.vercheck.outputs.bumped == 'true' && steps.releasecheck.outputs.exists == 'false'