diff --git a/app/assets/javascripts/filtered_search/available_dropdown_mappings.js b/app/assets/javascripts/filtered_search/available_dropdown_mappings.js
index adb3a683c33b89254ce385aca3d4bf6255063f28..e0281b8f443f3be503a003c5fb0345f8a3bdde20 100644
--- a/app/assets/javascripts/filtered_search/available_dropdown_mappings.js
+++ b/app/assets/javascripts/filtered_search/available_dropdown_mappings.js
@@ -204,7 +204,7 @@ export default class AvailableDropdownMappings {
   getMergeRequestTargetBranchesEndpoint() {
     const endpoint = `${
       gon.relative_url_root || ''
-    }/autocomplete/merge_request_target_branches.json`;
+    }/-/autocomplete/merge_request_target_branches.json`;
 
     const params = {
       group_id: this.getGroupId(),