diff --git a/src/toolkit/content/widgets/arrowscrollbox-js.patch b/src/toolkit/content/widgets/arrowscrollbox-js.patch
index 2c623529d..669f1b62e 100644
--- a/src/toolkit/content/widgets/arrowscrollbox-js.patch
+++ b/src/toolkit/content/widgets/arrowscrollbox-js.patch
@@ -1,12 +1,20 @@
 diff --git a/toolkit/content/widgets/arrowscrollbox.js b/toolkit/content/widgets/arrowscrollbox.js
-index 0b81a2bf5a0e1d745623f9b72fbe57254c1b16dd..f49ad7cb08f5d2be4a03046c191361f8c8a004bc 100644
+index f9191af09f1b7a1654aff62807e7dad573afc172..f49ad7cb08f5d2be4a03046c191361f8c8a004bc 100644
 --- a/toolkit/content/widgets/arrowscrollbox.js
 +++ b/toolkit/content/widgets/arrowscrollbox.js
-@@ -640,7 +640,7 @@
+@@ -98,6 +98,7 @@
+ 
+       let slot = this.shadowRoot.querySelector("slot");
+       let overflowObserver = new ResizeObserver(_ => {
++        if (this.id == 'tabbrowser-arrowscrollbox') return; // zen: do NOT underflow/overflow on tabbrowser-arrowscrollbox
+         let contentSize =
+           slot.getBoundingClientRect()[this.#verticalMode ? "height" : "width"];
+         // NOTE(emilio): This should be contentSize > scrollClientSize, but due
+@@ -639,7 +640,7 @@
  
      on_wheel(event) {
        // Don't consume the event if we can't scroll.
--      if (!this.overflowing || this.id === 'tabbrowser-arrowscrollbox' || (event.deltaY == 0 && this.classList.contains('workspace-arrowscrollbox'))) {
+-      if (!this.overflowing) {
 +      if (!this.overflowing || this.id === 'tabbrowser-arrowscrollbox' || ((event.deltaY == 0 || gZenWorkspaces._swipeState?.isGestureActive) && this.classList.contains('workspace-arrowscrollbox'))) {
          return;
        }