diff --git a/web/src/stream_list.ts b/web/src/stream_list.ts
index 77af1b8e1c..28c8b29915 100644
--- a/web/src/stream_list.ts
+++ b/web/src/stream_list.ts
@@ -677,7 +677,7 @@ export function get_sidebar_stream_topic_info(filter: Filter): {
     };
 
     const op_stream = filter.operands("channel");
-    if (op_stream.length === 0) {
+    if (op_stream[0] === undefined) {
         return result;
     }