diff --git a/app/javascript/src/javascripts/autocomplete.js b/app/javascript/src/javascripts/autocomplete.js
index c3b9ed615..55ddddbd9 100644
--- a/app/javascript/src/javascripts/autocomplete.js
+++ b/app/javascript/src/javascripts/autocomplete.js
@@ -97,7 +97,7 @@ Autocomplete.current_term = function($input) {
   let query = $input.get(0).value;
   let caret = $input.get(0).selectionStart;
   let regexp = new RegExp(`^[-~(]*(${Autocomplete.tag_prefixes().join("|")})?`);
-  let match = query.substring(0, caret).match(/\S*$/)[0].replace(regexp, "");
+  let match = query.substring(0, caret).match(/\S*$/)[0].replace(regexp, "").toLowerCase();
   return match;
 };