--- a/gfx/webrender_bindings/src/moz2d_renderer.rs
+++ b/gfx/webrender_bindings/src/moz2d_renderer.rs
@@ -488,16 +488,19 @@ impl BlobImageRenderer for Moz2dImageRen
         Err(BlobImageError::Other("Channel closed".into()))
     }
     fn delete_font(&mut self, font: FontKey) {
         unsafe { DeleteFontData(font); }
     }
 
     fn delete_font_instance(&mut self, _key: FontInstanceKey) {
     }
+
+    fn clear_namespace(&mut self, _namespace: IdNamespace) {
+    }
 }
 
 use bindings::WrFontKey;
 
 #[allow(improper_ctypes)] // this is needed so that rustc doesn't complain about passing the &Arc<Vec> to an extern function
 extern "C" {
     fn AddFontData(key: WrFontKey, data: *const u8, size: usize, index: u32, vec: &ArcVecU8);
     fn AddNativeFontHandle(key: WrFontKey, handle: *mut c_void, index: u32);