diff --git a/createdisk-library.sh b/createdisk-library.sh
index 282b6e1c..1d25ca45 100755
--- a/createdisk-library.sh
+++ b/createdisk-library.sh
@@ -6,7 +6,7 @@ function get_dest_dir_suffix {
     local version=$1
     DEST_DIR_SUFFIX="${version}_${yq_ARCH}"
     if [ -n "${PULL_NUMBER-}" ]; then
-         DEST_DIR_SUFFIX="$DEST_DIR_SUFFIX.pr${PULL_NUMBER}"
+         DEST_DIR_SUFFIX="${DEST_DIR_SUFFIX}_${PULL_NUMBER}"
     fi
 }