diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1ff0c9d..50a3b0c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -59,6 +59,8 @@ jobs:
       - name: Run attest-provenance
         id: attest-provenance
         uses: ./
+        env:
+          INPUT_PRIVATE-SIGNING: 'true'
         with:
           subject-digest: 'sha256:7d070f6b64d9bcc530fe99cc21eaaa4b3c364e0b2d367d7735671fa202a03b32'
           subject-name: 'subject'