diff --git a/.github/workflows/build_push.yml b/.github/workflows/build_push.yml
index 8822df4..96807e2 100644
--- a/.github/workflows/build_push.yml
+++ b/.github/workflows/build_push.yml
@@ -138,9 +138,10 @@ jobs:
         id: build-release
         shell: bash
         run: |
+          NORMALISED_IMAGE=$(${{ needs.build_publish.outputs.IMAGE }} | sed 's/\//_/g')
           echo "RELEASE_BODY=Check the artifacts in this release for more information about the published image." >> $GITHUB_OUTPUT
           echo "TAGGED_IMAGE=${{ needs.build_publish.outputs.IMAGE }}:${{ needs.build_publish.outputs.TAG }}" >> $GITHUB_OUTPUT
-          echo "MANIFEST_OUTPUT_FILENAME=image_manifest_${{ needs.build_publish.outputs.IMAGE }}.json" >> $GITHUB_OUTPUT
+          echo "MANIFEST_OUTPUT_FILENAME=image_manifest_$NORMALISED_IMAGE.json" >> $GITHUB_OUTPUT
           echo "R_PKG_OUTPUT_FILENAME=R_package_list_${{ needs.build_publish.outputs.IMAGE }}.csv" >> $GITHUB_OUTPUT
           echo "SBOM_OUTPUT_FILENAME='SBOM for ${{ needs.build_publish.outputs.IMAGE }}.spdx.json'" >> $GITHUB_OUTPUT