diff --git a/assets/runtime/functions b/assets/runtime/functions
index cd03cd82..ac2bab4c 100644
--- a/assets/runtime/functions
+++ b/assets/runtime/functions
@@ -957,7 +957,7 @@ map_uidgid() {
   USERMAP_UID=${USERMAP_UID:-$USERMAP_ORIG_UID}
   if [[ ${USERMAP_UID} != ${USERMAP_ORIG_UID} ]] || [[ ${USERMAP_GID} != ${USERMAP_ORIG_GID} ]]; then
     echo "Mapping UID and GID for ${GITLAB_USER}:${GITLAB_USER} to $USERMAP_UID:$USERMAP_GID"
-    groupmod -g ${USERMAP_GID} ${GITLAB_USER}
+    groupmod -o -g ${USERMAP_GID} ${GITLAB_USER}
     sed -i -e "s|:${USERMAP_ORIG_UID}:${USERMAP_GID}:|:${USERMAP_UID}:${USERMAP_GID}:|" /etc/passwd
     find ${GITLAB_HOME} -path ${GITLAB_DATA_DIR}/\* -prune -o -print0 | xargs -0 chown -h ${GITLAB_USER}:
   fi