diff --git a/dom/canvas/WebGLContext.cpp b/dom/canvas/WebGLContext.cpp
index b810a75fae82..eb05cd592a45 100644
--- a/dom/canvas/WebGLContext.cpp
+++ b/dom/canvas/WebGLContext.cpp
@@ -669,6 +669,12 @@ CreateOffscreen(GLContext* gl,
     if (!baseCaps.alpha)
         baseCaps.premultAlpha = true;
 
+    if (gl->IsANGLE()) {
+        // We can't use no-alpha formats on ANGLE yet because of:
+        // https://code.google.com/p/angleproject/issues/detail?id=764
+        baseCaps.alpha = true;
+    }
+
     // we should really have this behind a
     // |gfxPlatform::GetPlatform()->GetScreenDepth() == 16| check, but
     // for now it's just behind a pref for testing/evaluation.
@@ -928,6 +934,12 @@ WebGLContext::SetDimensions(int32_t sWidth, int32_t sHeight)
 
     mShouldPresent = true;
 
+    if (gl->WorkAroundDriverBugs()) {
+        if (!mOptions.alpha && gl->Caps().alpha) {
+            mNeedsFakeNoAlpha = true;
+        }
+    }
+
     MOZ_ASSERT(gl->Caps().color);
     MOZ_ASSERT(gl->Caps().alpha == mOptions.alpha);
     MOZ_ASSERT(gl->Caps().depth == mOptions.depth);
@@ -935,12 +947,6 @@ WebGLContext::SetDimensions(int32_t sWidth, int32_t sHeight)
     MOZ_ASSERT(gl->Caps().antialias == mOptions.antialias);
     MOZ_ASSERT(gl->Caps().preserve == mOptions.preserveDrawingBuffer);
 
-    if (gl->WorkAroundDriverBugs() && gl->IsANGLE()) {
-        if (!mOptions.alpha) {
-            mNeedsFakeNoAlpha = true;
-        }
-    }
-
     AssertCachedBindings();
     AssertCachedState();
 
@@ -1845,7 +1851,6 @@ bool WebGLContext::TexImageFromVideoElement(const TexImageTarget texImageTarget,
 
 ////////////////////////////////////////////////////////////////////////////////
 
-
 WebGLContext::ScopedMaskWorkaround::ScopedMaskWorkaround(WebGLContext& webgl)
     : mWebGL(webgl)
     , mNeedsChange(NeedsChange(webgl))
diff --git a/dom/canvas/WebGLContextState.cpp b/dom/canvas/WebGLContextState.cpp
index 474734bbfac7..4164357c5989 100644
--- a/dom/canvas/WebGLContextState.cpp
+++ b/dom/canvas/WebGLContextState.cpp
@@ -312,12 +312,18 @@ WebGLContext::GetParameter(JSContext* cx, GLenum pname, ErrorResult& rv)
         case LOCAL_GL_RED_BITS:
         case LOCAL_GL_GREEN_BITS:
         case LOCAL_GL_BLUE_BITS:
-        case LOCAL_GL_ALPHA_BITS:
         case LOCAL_GL_DEPTH_BITS: {
             GLint i = 0;
             gl->fGetIntegerv(pname, &i);
             return JS::Int32Value(i);
         }
+        case LOCAL_GL_ALPHA_BITS: {
+            GLint i = 0;
+            if (!mNeedsFakeNoAlpha) {
+                gl->fGetIntegerv(pname, &i);
+            }
+            return JS::Int32Value(i);
+        }
         case LOCAL_GL_FRAGMENT_SHADER_DERIVATIVE_HINT: {
             if (IsExtensionEnabled(WebGLExtensionID::OES_standard_derivatives)) {
                 GLint i = 0;
diff --git a/gfx/gl/SharedSurfaceANGLE.cpp b/gfx/gl/SharedSurfaceANGLE.cpp
index 7c871ae5aea7..7143ca134c9c 100644
--- a/gfx/gl/SharedSurfaceANGLE.cpp
+++ b/gfx/gl/SharedSurfaceANGLE.cpp
@@ -289,7 +289,9 @@ ChooseConfig(GLContext* gl, GLLibraryEGL* egl, const SurfaceCaps& caps)
     EGLConfig config = EGL_NO_CONFIG;
     for (int i = 0; i < foundConfigs; i++) {
         EGLConfig cur = configs[i];
-        if (!DoesAttribBitsMatchCapBool(egl, cur, LOCAL_EGL_DEPTH_SIZE,
+        if (!DoesAttribBitsMatchCapBool(egl, cur, LOCAL_EGL_ALPHA_SIZE,
+                                        caps.alpha) ||
+            !DoesAttribBitsMatchCapBool(egl, cur, LOCAL_EGL_DEPTH_SIZE,
                                         caps.depth) ||
             !DoesAttribBitsMatchCapBool(egl, cur, LOCAL_EGL_STENCIL_SIZE,
                                         caps.stencil))
@@ -297,16 +299,6 @@ ChooseConfig(GLContext* gl, GLLibraryEGL* egl, const SurfaceCaps& caps)
             continue;
         }
 
-        // We can't enforce alpha on ANGLE yet because of:
-        // https://code.google.com/p/angleproject/issues/detail?id=764
-        if (!gl->IsANGLE()) {
-            if (!DoesAttribBitsMatchCapBool(egl, cur, LOCAL_EGL_ALPHA_SIZE,
-                                            caps.alpha))
-            {
-                continue;
-            }
-        }
-
         config = cur;
         break;
     }