diff --git a/components/style/custom_properties.rs b/components/style/custom_properties.rs
index 7e8a1e37f7f..96328d9a51a 100644
--- a/components/style/custom_properties.rs
+++ b/components/style/custom_properties.rs
@@ -75,8 +75,13 @@ fn get_titlebar_radius(device: &Device) -> VariableValue {
     VariableValue::pixel(device.titlebar_radius())
 }
 
-static CHROME_ENVIRONMENT_VARIABLES: [EnvironmentVariable; 1] = [
+fn get_menu_radius(device: &Device) -> VariableValue {
+    VariableValue::pixel(device.menu_radius())
+}
+
+static CHROME_ENVIRONMENT_VARIABLES: [EnvironmentVariable; 2] = [
     make_variable!(atom!("-moz-gtk-csd-titlebar-radius"), get_titlebar_radius),
+    make_variable!(atom!("-moz-gtk-menu-radius"), get_menu_radius),
 ];
 
 impl CssEnvironment {
diff --git a/components/style/gecko/media_queries.rs b/components/style/gecko/media_queries.rs
index b41280d2112..6e82404de1d 100644
--- a/components/style/gecko/media_queries.rs
+++ b/components/style/gecko/media_queries.rs
@@ -447,6 +447,13 @@ impl Device {
         }
     }
 
+    /// Returns the gtk menu radius in CSS pixels.
+    pub fn menu_radius(&self) -> f32 {
+        unsafe {
+            bindings::Gecko_GetLookAndFeelInt(bindings::LookAndFeel_IntID::GtkMenuRadius as i32) as f32
+        }
+    }
+
     /// Return whether the document is a chrome document.
     #[inline]
     pub fn is_chrome_document(&self) -> bool {