diff --git a/apps/web/src/components/ui/sidebar.tsx b/apps/web/src/components/ui/sidebar.tsx
index 425db645736a..a05b09754f0a 100644
--- a/apps/web/src/components/ui/sidebar.tsx
+++ b/apps/web/src/components/ui/sidebar.tsx
@@ -708,8 +708,9 @@ function SidebarContent({
         className="h-auto min-h-0 flex-1"
       >
         <div
+          // Reordered rows must not pull the viewport to their new position.
           className={cn(
-            "flex w-full min-w-0 flex-col gap-2 group-data-[collapsible=icon]:overflow-hidden",
+            "flex w-full min-w-0 flex-col gap-2 [overflow-anchor:none] group-data-[collapsible=icon]:overflow-hidden",
             className,
           )}
           data-sidebar="content"
diff --git a/docs/user/thread-sidebar.md b/docs/user/thread-sidebar.md
index b2c244a6123e..69d0099032c9 100644
--- a/docs/user/thread-sidebar.md
+++ b/docs/user/thread-sidebar.md
@@ -29,6 +29,9 @@ the thread opens and the files are attached in its composer, ready for
 your next message. The same per-message file limits apply as when attaching
 files directly; see [Attach files](./composer.md#attach-files).
 
+On web and desktop, pinning or unpinning a thread keeps the sidebar at your current
+scroll position instead of following the thread to its new place in the list.
+
 Pinning does not prevent automatic settlement. Settling a thread removes its pin.
 
 On web and desktop, drag a thread between sections to change its state. Drag a thread up into