diff --git a/css/leptonChrome.css b/css/leptonChrome.css
index 5e0f1a9..4e9a979 100644
--- a/css/leptonChrome.css
+++ b/css/leptonChrome.css
@@ -317,16 +317,18 @@
     }
   }
   /*= Titlebar Container Size at maximized #384 ================================*/
-  @media (-moz-os-version: windows-win7),
-    (-moz-platform: windows-win7),
-    (-moz-os-version: windows-win8),
-    (-moz-platform: windows-win8),
-    (-moz-os-version: windows-win10),
-    (-moz-platform: windows-win10) {
-    :root[tabsintitlebar][sizemode="maximized"] #titlebar {
-      /* -moz-default-appearance: -moz-window-titlebar */
-      appearance: none !important;
-      padding-top: 8px;
+  @supports -moz-bool-pref("userChrome.compatibility.os.windows_maximized") {
+    @media (-moz-os-version: windows-win7),
+      (-moz-platform: windows-win7),
+      (-moz-os-version: windows-win8),
+      (-moz-platform: windows-win8),
+      (-moz-os-version: windows-win10),
+      (-moz-platform: windows-win10) {
+      :root[tabsintitlebar][sizemode="maximized"] #titlebar {
+        /* -moz-default-appearance: -moz-window-titlebar */
+        appearance: none !important;
+        padding-top: 8px;
+      }
     }
   }
 }
diff --git a/src/compatibility/_os.scss b/src/compatibility/_os.scss
index 2137dc7..26d8e87 100644
--- a/src/compatibility/_os.scss
+++ b/src/compatibility/_os.scss
@@ -181,12 +181,14 @@ $_os_linuxDefaultShadow: 0 0 4px rgba(128, 128, 142, 0.5);
 }
 
 /*= Titlebar Container Size at maximized #384 ================================*/
-@include OS($win) {
-  :root[tabsintitlebar][sizemode="maximized"] #titlebar {
-    /* -moz-default-appearance: -moz-window-titlebar */
-    appearance: none !important;
+@include Option("userChrome.compatibility.os.windows_maximized") {
+  @include OS($win) {
+    :root[tabsintitlebar][sizemode="maximized"] #titlebar {
+      /* -moz-default-appearance: -moz-window-titlebar */
+      appearance: none !important;
 
-    // Prevent sideeffect #370
-    padding-top: 8px; // Don't use margin-top for reserved fullscreen animation
+      // Prevent sideeffect #370
+      padding-top: 8px; // Don't use margin-top for reserved fullscreen animation
+    }
   }
 }
diff --git a/user.js b/user.js
index 75b6d71..c5d9fa4 100644
--- a/user.js
+++ b/user.js
@@ -61,6 +61,7 @@ user_pref("userChrome.tab.bottom_rounded_corner",      true);
 // user_pref("userChrome.compatibility.dynamic_separator",    true); // Need dynamic_seperator
 
 // user_pref("userChrome.compatiblity.os.linux_non_native_titlebar_button", true);
+// user_pref("userChrome.compatibility.os.windows_maximized, true");
 
 // == Theme Custom Settings ====================================================
 // -- User Chrome --------------------------------------------------------------