diff --git a/.github/workflows/build-docker.yml b/.github/workflows/build-docker.yml
index 93fe76a04..49495f5ac 100644
--- a/.github/workflows/build-docker.yml
+++ b/.github/workflows/build-docker.yml
@@ -262,8 +262,11 @@ jobs:
             "amd-alpine-24-${RUN_ID}" \
             "arm-alpine-24-${RUN_ID}"; do
 
-            SIZE=$(skopeo inspect --raw --creds "${GHCR_CREDS}" \
+            DIGEST=$(skopeo inspect --raw --creds "${GHCR_CREDS}" \
               "docker://${REGISTRY}:${TAG}" | \
+              jq -r '.manifests[0].digest')
+            SIZE=$(skopeo inspect --raw --creds "${GHCR_CREDS}" \
+              "docker://${REGISTRY}@${DIGEST}" | \
               jq '[.layers[].size] | add')
 
             echo "${TIMESTAMP},${COMMIT},${TAG},${SIZE}" >> "$CSV"