diff --git a/web/src/scroll_util.ts b/web/src/scroll_util.ts
index ded4918427..b54b591fa8 100644
--- a/web/src/scroll_util.ts
+++ b/web/src/scroll_util.ts
@@ -1,5 +1,4 @@
 import $ from "jquery";
-import assert from "minimalistic-assert";
 import SimpleBar from "simplebar";
 
 // This type is helpful for testing, where we may have a dummy object instead of an actual jquery object.
@@ -7,9 +6,8 @@ type JQueryOrZJQuery = {__zjquery?: true} & JQuery;
 
 export function get_content_element($element: JQuery): JQuery {
     const element = $element.expectOne()[0];
-    const sb: unknown = SimpleBar.instances.get(element);
+    const sb = SimpleBar.instances.get(element);
     if (sb) {
-        assert(sb instanceof SimpleBar); // https://github.com/Grsmto/simplebar/pull/689
         return $(sb.getContentElement()!);
     }
     return $element;
@@ -22,9 +20,8 @@ export function get_scroll_element($element: JQueryOrZJQuery): JQuery {
     }
 
     const element = $element.expectOne()[0];
-    const sb: unknown = SimpleBar.instances.get(element);
+    const sb = SimpleBar.instances.get(element);
     if (sb) {
-        assert(sb instanceof SimpleBar); // https://github.com/Grsmto/simplebar/pull/689
         return $(sb.getScrollElement()!);
     } else if ("simplebar" in element.dataset) {
         // The SimpleBar mutation observer hasn’t processed this element yet.
@@ -36,9 +33,8 @@ export function get_scroll_element($element: JQueryOrZJQuery): JQuery {
 
 export function reset_scrollbar($element: JQuery): void {
     const element = $element.expectOne()[0];
-    const sb: unknown = SimpleBar.instances.get(element);
+    const sb = SimpleBar.instances.get(element);
     if (sb) {
-        assert(sb instanceof SimpleBar); // https://github.com/Grsmto/simplebar/pull/689
         sb.getScrollElement()!.scrollTop = 0;
     } else {
         element.scrollTop = 0;