diff --git a/chrome/content/zotero/elements/itemPaneSidenav.js b/chrome/content/zotero/elements/itemPaneSidenav.js
index 8bde7496da..6d4be2b178 100644
--- a/chrome/content/zotero/elements/itemPaneSidenav.js
+++ b/chrome/content/zotero/elements/itemPaneSidenav.js
@@ -608,6 +608,11 @@
 			// Keep in sync with _itemPaneSidenav.scss
 			let btnSize = 28;
 			let btnGap = 6;
+			let btnToggleSize = 42;
+
+			let isStacked = this.classList.contains("stacked");
+			let baseSize = isStacked ? 0 : btnToggleSize;
+
 			// Before the center of the button, insert before it; otherwise, insert after it.
 			let index = 0;
 			if (offset < btnSize / 2) {
@@ -619,7 +624,7 @@
 			}
 			return {
 				index,
-				position: index === 0 ? 0 : index * (btnSize + btnGap) + btnGap / 2
+				position: (index === 0 ? 0 : index * (btnSize + btnGap) + btnGap / 2) + baseSize
 			};
 		};