diff --git a/src/out b/src/out
index 8a96dd1..563425c 100755
--- a/src/out
+++ b/src/out
@@ -14,8 +14,11 @@ cd - 1>&2 2>/dev/null
 crane push "$oci_dir" "$REPOSITORY:$TAG" --image-refs="$image_refs_file"
 additional_tags="$(jq -r .params.additional_tags < "$INPUT_FILE")"
 if [ -n "$additional_tags" ]; then
+    if [ -r "$1/$additional_tags" ]; then
+        fail "cannot open file $1/$additional_tags"
+    fi
     tr '[:space:]' '\n' < "$1/$additional_tags" | grep -v '^$' | while read -r tag; do
-        crane tag "$REPOSITORY:@$(cat "$image_refs_file")" "$tag"
+        crane tag "$REPOSITORY:@$(sed 's/^[^@]*@//' < "$image_refs_file")" "$tag"
     done
 fi