diff --git a/chrome/content/zotero/containers/tagSelectorContainer.jsx b/chrome/content/zotero/containers/tagSelectorContainer.jsx
index 0bdf1c63e7..57ca342c6d 100644
--- a/chrome/content/zotero/containers/tagSelectorContainer.jsx
+++ b/chrome/content/zotero/containers/tagSelectorContainer.jsx
@@ -508,7 +508,11 @@ Zotero.TagSelector = class TagSelectorContainer extends React.PureComponent {
 			tagContextMenu.childNodes[i].disabled = this.state.viewOnly;
 		}
 		ev.preventDefault();
-		tagContextMenu.openPopup(null, null, ev.clientX+2, ev.clientY+2);
+		tagContextMenu.openPopupAtScreen(
+			window.screenX + ev.clientX + 2,
+			window.screenY + ev.clientY + 2,
+			true
+		);
 		this.contextTag = tag;
 	}
 
diff --git a/chrome/content/zotero/itemTree.jsx b/chrome/content/zotero/itemTree.jsx
index 67ee178162..9fcafc109c 100644
--- a/chrome/content/zotero/itemTree.jsx
+++ b/chrome/content/zotero/itemTree.jsx
@@ -3744,7 +3744,11 @@ var ItemTree = class ItemTree extends LibraryTree {
 		menupopup.appendChild(menuitem);
 		
 		document.children[0].appendChild(menupopup);
-		menupopup.openPopup(null, null, event.clientX + 2, event.clientY + 2);
+		menupopup.openPopupAtScreen(
+			window.screenX + event.clientX + 2,
+			window.screenY + event.clientY + 2,
+			true
+		);
 	}
 
 	_getSecondarySortField() {