diff --git a/src/out b/src/out
index 58bd825..af644c1 100755
--- a/src/out
+++ b/src/out
@@ -12,7 +12,7 @@ tar xf "$1/$(jq -r .params.image < "$INPUT_FILE")"
 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")"
+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"