diff --git a/web/src/filter.ts b/web/src/filter.ts
index 3c7d62746d..2aa39bba03 100644
--- a/web/src/filter.ts
+++ b/web/src/filter.ts
@@ -1626,10 +1626,8 @@ export class Filter {
         return new Filter(terms);
     }
 
-    has_topic(stream_id: number, topic: string): boolean {
-        return (
-            this.has_operand("channel", stream_id.toString()) && this.has_operand("topic", topic)
-        );
+    has_topic(stream_id: string, topic: string): boolean {
+        return this.has_operand("channel", stream_id) && this.has_operand("topic", topic);
     }
 
     sorted_term_types(): string[] {
diff --git a/web/src/message_events.ts b/web/src/message_events.ts
index 919f9428a5..920337336a 100644
--- a/web/src/message_events.ts
+++ b/web/src/message_events.ts
@@ -679,7 +679,7 @@ export function update_messages(events: UpdateMessageEvent[]): void {
                 // Code further down takes care of the actual rerendering of
                 // messages within a narrow.
                 selection_changed_topic &&
-                current_filter?.has_topic(old_stream_id, orig_topic)
+                current_filter?.has_topic(String(old_stream_id), orig_topic)
             ) {
                 let new_filter = current_filter;
                 if (new_filter && stream_changed) {