--- a/dom/canvas/WebGLContext.cpp
+++ b/dom/canvas/WebGLContext.cpp
@@ -70,16 +70,20 @@
 #include "WebGLTransformFeedback.h"
 #include "WebGLVertexArray.h"
 #include "WebGLVertexAttribData.h"
 
 #ifdef MOZ_WIDGET_COCOA
 #include "nsCocoaFeatures.h"
 #endif
 
+#ifdef XP_WIN
+#include "WGLLibrary.h"
+#endif
+
 // Generated
 #include "mozilla/dom/WebGLRenderingContextBinding.h"
 
 
 namespace mozilla {
 
 using namespace mozilla::dom;
 using namespace mozilla::gfx;
@@ -947,18 +951,30 @@ WebGLContext::SetDimensions(int32_t sign
 
             text.AppendASCII("\n* ");
             text.Append(cur.info);
         }
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
     }
     MOZ_ASSERT(gl);
+    MOZ_ASSERT_IF(mOptions.alpha, gl->Caps().alpha);
 
-    MOZ_ASSERT_IF(mOptions.alpha, gl->Caps().alpha);
+#ifdef XP_WIN
+    if (failIfPerfCaveat &&
+        gl->GetContextType() == gl::GLContextType::WGL &&
+        !gl::sWGLLib.HasDXInterop2())
+    {
+        gl = nullptr;
+
+        const nsLiteralCString text("Caveat: WGL without DXGLInterop2.");
+        ThrowEvent_WebGLContextCreationError(text);
+        return NS_ERROR_FAILURE;
+    }
+#endif
 
     if (!ResizeBackbuffer(width, height)) {
         Telemetry::Accumulate(Telemetry::CANVAS_WEBGL_FAILURE_ID,
                               NS_LITERAL_CSTRING("FEATURE_FAILURE_WEBGL_RESIZE"));
         const nsLiteralCString text("Initializing WebGL backbuffer failed.");
         ThrowEvent_WebGLContextCreationError(text);
         return NS_ERROR_FAILURE;
     }