diff --git a/web/src/peer_data.ts b/web/src/peer_data.ts
index 7a087b5916..30074f7f58 100644
--- a/web/src/peer_data.ts
+++ b/web/src/peer_data.ts
@@ -11,17 +11,9 @@ export function clear_for_testing(): void {
     stream_subscribers.clear();
 }
 
-function assert_number(id: number): void {
-    if (typeof id !== "number") {
-        blueslip.error("You must pass ids as numbers to peer_data", {id});
-    }
-}
-
 function get_user_set(stream_id: number): LazySet {
     // This is an internal function to get the LazySet of users.
     // We create one on the fly as necessary, but we warn in that case.
-    assert_number(stream_id);
-
     if (!sub_store.get(stream_id)) {
         blueslip.warn(`We called get_user_set for an untracked stream: ${stream_id}`);
     }
diff --git a/web/tests/peer_data.test.js b/web/tests/peer_data.test.js
index a92704de1b..169a9fa6bc 100644
--- a/web/tests/peer_data.test.js
+++ b/web/tests/peer_data.test.js
@@ -275,7 +275,6 @@ test("is_subscriber_subset", () => {
     blueslip.reset();
 
     // Warn about hypothetical undefined stream_ids.
-    blueslip.expect("error", "You must pass ids as numbers to peer_data");
     blueslip.expect("warn", "We called get_user_set for an untracked stream: undefined");
     peer_data.is_subscriber_subset(undefined, sub_a.stream_id);
     blueslip.reset();