diff --git a/gfx/thebes/gfxWindowsPlatform.cpp b/gfx/thebes/gfxWindowsPlatform.cpp
index b24a41bb527d..2157c5ff98ca 100644
--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -482,6 +482,7 @@ gfxWindowsPlatform::UpdateRenderMode()
 #ifdef USE_D2D1_1
       if (gfxPrefs::Direct2DUse1_1() && Factory::SupportsD2D1()) {
         contentMask |= BackendTypeBit(BackendType::DIRECT2D1_1);
+        canvasMask |= BackendTypeBit(BackendType::DIRECT2D1_1);
         defaultBackend = BackendType::DIRECT2D1_1;
       } else {
 #endif