diff --git a/gfx/thebes/gfxWindowsPlatform.cpp b/gfx/thebes/gfxWindowsPlatform.cpp
index c1bef33eacbf..1a2a4c8f01b6 100755
--- a/gfx/thebes/gfxWindowsPlatform.cpp
+++ b/gfx/thebes/gfxWindowsPlatform.cpp
@@ -557,6 +557,7 @@ gfxWindowsPlatform::UpdateRenderMode()
 
       imgLoader::Singleton()->ClearCache(true);
       imgLoader::Singleton()->ClearCache(false);
+      gfxAlphaBoxBlur::ShutdownBlurCache();
       Factory::SetDirect3D11Device(nullptr);
 
       didReset = true;