diff --git a/chrome/content/zotero-platform/unix/overlay.css b/chrome/content/zotero-platform/unix/overlay.css
index 256389b53c..5518adfb4b 100644
--- a/chrome/content/zotero-platform/unix/overlay.css
+++ b/chrome/content/zotero-platform/unix/overlay.css
@@ -86,6 +86,10 @@
 	box-shadow: var(--toolbarbutton-active-boxshadow);
 	transition-duration: 10ms;
 }
+
+#zotero-toolbar-main-button-single[cui-areatype="toolbar"] .toolbarbutton-icon {
+	width: 32px;
+}
 /* End toolbar buttons */
 
 
diff --git a/chrome/content/zotero-platform/win/overlay.css b/chrome/content/zotero-platform/win/overlay.css
index e309c6baf5..73eb1ff8b8 100644
--- a/chrome/content/zotero-platform/win/overlay.css
+++ b/chrome/content/zotero-platform/win/overlay.css
@@ -94,6 +94,10 @@
 #zotero-toolbar-save-button[cui-areatype="toolbar"] > menupopup {
 	margin-top: -5px;
 }
+
+#zotero-toolbar-main-button-single[cui-areatype="toolbar"] .toolbarbutton-icon {
+	width: 32px;
+}
 /* End toolbar buttons */
 
 #zotero-tb-search-menu-button {