diff --git a/src/gtk3/applications/_firefox.scss b/src/gtk3/applications/_firefox.scss
new file mode 100644
index 0000000..86054ff
--- /dev/null
+++ b/src/gtk3/applications/_firefox.scss
@@ -0,0 +1,8 @@
+#MozillaGtkWidget {
+    scrollbar {
+        margin: 0px;
+        slider {
+            border: 5px solid transparent;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/gtk3/gtk.scss b/src/gtk3/gtk.scss
index b4ef581..1251e4b 100644
--- a/src/gtk3/gtk.scss
+++ b/src/gtk3/gtk.scss
@@ -1,38 +1,39 @@
 @charset "UTF-8";
 
 $new-highlight: false;
 
 @import 'global';
 @import '../functions';
 @import '../colors';
 
 @import "widgets/base";
 @import "widgets/button";
 @import "widgets/entry";
 @import "widgets/app_notifications";
 @import "widgets/calendar";
 @import "widgets/checkboxes";
 @import "widgets/color_chooser";
 @import "widgets/dialogs";
 @import "widgets/headerbar";
 @import "widgets/infobar";
 @import "widgets/link";
 @import "widgets/lists";
 @import "widgets/menus";
 @import "widgets/misc";
 @import "widgets/notebook";
 @import "widgets/overshoot";
 @import "widgets/pathbar";
 @import "widgets/progressbar";
 @import "widgets/scale";
 @import "widgets/scrollbar";
 @import "widgets/sidebar";
 @import "widgets/spinbutton";
 @import "widgets/switch";
 @import "widgets/toolbar";
 @import "widgets/tooltips";
 @import "widgets/treeview";
 @import "widgets/window_decorations";
 @import "widgets/libhandy";
 
-@import "applications/chromium";
\ No newline at end of file
+@import "applications/chromium";
+@import "applications/firefox";
\ No newline at end of file