--- a/gfx/gl/GLContextProviderEGL.cpp
+++ b/gfx/gl/GLContextProviderEGL.cpp
@@ -79,16 +79,19 @@ using namespace mozilla::widget;
 
 #define ADD_ATTR_1(_array, _k) do {             \
     (_array).AppendElement(_k);                 \
 } while (0)
 
 static bool
 CreateConfig(EGLConfig* aConfig, bool aEnableDepthBuffer);
 
+static bool
+CreateConfig(EGLConfig* aConfig, int32_t depth, bool aEnableDepthBuffer);
+
 // append three zeros at the end of attribs list to work around
 // EGL implementation bugs that iterate until they find 0, instead of
 // EGL_NONE. See bug 948406.
 #define EGL_ATTRIBS_LIST_SAFE_TERMINATION_WORKING_AROUND_BUGS \
      LOCAL_EGL_NONE, 0, 0, 0
 
 static EGLint kTerminationAttribs[] = {
     EGL_ATTRIBS_LIST_SAFE_TERMINATION_WORKING_AROUND_BUGS
@@ -172,19 +175,29 @@ GLContextEGLFactory::Create(EGLNativeWin
     if (!sEGLLibrary.EnsureInitialized(false, &discardFailureId)) {
         gfxCriticalNote << "Failed to load EGL library 3!";
         return nullptr;
     }
 
     bool doubleBuffered = true;
 
     EGLConfig config;
-    if (!CreateConfig(&config, aWebRender)) {
-        gfxCriticalNote << "Failed to create EGLConfig!";
-        return nullptr;
+    if (aWebRender && sEGLLibrary.IsANGLE()) {
+        // Force enable alpha channel to make sure ANGLE use correct framebuffer formart
+        const int bpp = 32;
+        const bool withDepth = true;
+        if (!CreateConfig(&config, bpp, withDepth)) {
+            gfxCriticalNote << "Failed to create EGLConfig for WebRender ANGLE!";
+            return nullptr;
+        }
+    } else {
+        if (!CreateConfig(&config, aWebRender)) {
+            gfxCriticalNote << "Failed to create EGLConfig!";
+            return nullptr;
+        }
     }
 
     EGLSurface surface = mozilla::gl::CreateSurfaceFromNativeWindow(aWindow, config);
 
     if (!surface) {
         gfxCriticalNote << "Failed to create EGLSurface!";
         return nullptr;
     }