diff --git a/src/zen/workspaces/ZenWorkspaces.mjs b/src/zen/workspaces/ZenWorkspaces.mjs
index 84ab4025b..9f1eba7c7 100644
--- a/src/zen/workspaces/ZenWorkspaces.mjs
+++ b/src/zen/workspaces/ZenWorkspaces.mjs
@@ -2539,13 +2539,15 @@ var gZenWorkspaces = new (class extends ZenMultiWindowFeature {
   }
 
   async updateTabsContainers(target = undefined, forAnimation = false) {
-    if (target && !target.parentNode) {
+    if (target && !target.target?.parentNode) {
       target = null;
     }
     // Only animate if it's from an event
-    const animateContainer = target && target instanceof EventTarget;
+    const animateContainer = target && target.target instanceof EventTarget;
     await this.onPinnedTabsResize(
-      [{ target: target ?? this.pinnedTabsContainer }],
+      // This is what happens when we join a resize observer, an event listener
+      // while using it as a method.
+      [{ target: (target?.target ? target.target : target) ?? this.pinnedTabsContainer }],
       forAnimation,
       animateContainer
     );
diff --git a/src/zen/workspaces/zen-workspaces.css b/src/zen/workspaces/zen-workspaces.css
index 9b7aee08a..1faa67e50 100644
--- a/src/zen/workspaces/zen-workspaces.css
+++ b/src/zen/workspaces/zen-workspaces.css
@@ -527,6 +527,11 @@ zen-workspace {
       scrollbar-color: var(--vertical-tabs-scrollbar-color);
       overflow-y: auto;
     }
+
+    &,
+    & .zen-workspace-normal-tabs-section {
+      height: 100%;
+    }
   }
 }