diff --git a/toolkit/themes/linux/global/toolbarbutton.css b/toolkit/themes/linux/global/toolbarbutton.css
index cb3ea05c7035..dacf42ed063d 100644
--- a/toolkit/themes/linux/global/toolbarbutton.css
+++ b/toolkit/themes/linux/global/toolbarbutton.css
@@ -87,7 +87,7 @@ toolbarbutton:-moz-lwtheme:not(:hover, [checked="true"], [open="true"], [disable
   margin: -5px 0 0 !important;
   margin-inline-end: -4px !important;
   min-width: 14px;
-  max-width: 24px;
+  max-width: 20px;
   line-height: 10px;
   text-align: center;
   align-self: start;
diff --git a/toolkit/themes/osx/global/toolbarbutton.css b/toolkit/themes/osx/global/toolbarbutton.css
index 318655d18d5b..8ef5b24bc65b 100644
--- a/toolkit/themes/osx/global/toolbarbutton.css
+++ b/toolkit/themes/osx/global/toolbarbutton.css
@@ -50,7 +50,7 @@ toolbarbutton[disabled="true"] {
   margin: -5px 0 0 !important;
   margin-inline-end: -4px !important;
   min-width: 14px;
-  max-width: 24px;
+  max-width: 20px;
   line-height: 10px;
   text-align: center;
   align-self: start;
diff --git a/toolkit/themes/windows/global/toolbarbutton.css b/toolkit/themes/windows/global/toolbarbutton.css
index 071cf7eb4905..6d8b0e821434 100644
--- a/toolkit/themes/windows/global/toolbarbutton.css
+++ b/toolkit/themes/windows/global/toolbarbutton.css
@@ -93,7 +93,7 @@ toolbarbutton[disabled="true"] {
   margin: -5px 0 0 !important;
   margin-inline-end: -4px !important;
   min-width: 14px;
-  max-width: 24px;
+  max-width: 20px;
   line-height: 10px;
   text-align: center;
   align-self: start;