diff --git a/gm/lighting.cpp b/gm/lighting.cpp
index 46474ab..9db34fd 100644
--- a/gm/lighting.cpp
+++ b/gm/lighting.cpp
@@ -47,6 +47,18 @@
             make_bitmap();
             fInitialized = true;
         }
+        canvas->clear(0xFF101010);
+        SkPaint checkPaint;
+        checkPaint.setColor(0xFF202020);
+        for (int y = 0; y < HEIGHT; y += 16) {
+          for (int x = 0; x < WIDTH; x += 16) {
+            canvas->save();
+            canvas->translate(SkIntToScalar(x), SkIntToScalar(y));
+            canvas->drawRect(SkRect::MakeXYWH(8, 0, 8, 8), checkPaint);
+            canvas->drawRect(SkRect::MakeXYWH(0, 8, 8, 8), checkPaint);
+            canvas->restore();
+          }
+        }
         SkPoint3 pointLocation(0, 0, SkIntToScalar(10));
         SkScalar azimuthRad = SkDegreesToRadians(SkIntToScalar(225));
         SkScalar elevationRad = SkDegreesToRadians(SkIntToScalar(5));
diff --git a/src/effects/SkLightingImageFilter.cpp b/src/effects/SkLightingImageFilter.cpp
index a83fe58..f17318c 100644
--- a/src/effects/SkLightingImageFilter.cpp
+++ b/src/effects/SkLightingImageFilter.cpp
@@ -1286,7 +1286,8 @@
     SkString lightBody;
     lightBody.appendf("\tvec3 halfDir = vec3(normalize(surfaceToLight + vec3(0, 0, 1)));\n");
     lightBody.appendf("\tfloat colorScale = %s * pow(dot(normal, halfDir), %s);\n", ks, shininess);
-    lightBody.appendf("\treturn vec4(lightColor * clamp(colorScale, 0.0, 1.0), 1.0);\n");
+    lightBody.appendf("\tvec3 color = lightColor * clamp(colorScale, 0.0, 1.0);\n");
+    lightBody.appendf("\treturn vec4(color, max(max(color.r, color.g), color.b));\n");
     builder->emitFunction(GrGLShaderBuilder::kFragment_ShaderType,
                           kVec4f_GrSLType,
                           "light",