diff --git a/content/canvas/test/reftest/reftest.list b/content/canvas/test/reftest/reftest.list
index 2cc76a323100..ce27ccf2b4f2 100644
--- a/content/canvas/test/reftest/reftest.list
+++ b/content/canvas/test/reftest/reftest.list
@@ -156,7 +156,11 @@ fuzzy(1,65536) random-if(B2G) fuzzy-if(Android,9,65536)
 
 # Test over-bright premult:
 # random-if(B2G) from bug 983650
-fuzzy(1,65536) random-if(B2G) fuzzy-if(Android,9,65536) random-if(Android&&AndroidVersion<15)  == webgl-color-alpha-test.html?colorVal=1.0&alphaVal=0.5&alpha&premult  wrapper.html?colors-half-alpha.png
+# This test assumes that the compositor is able to correctly handle superluminant
+# pixels in a WebGL canvas with premultiplied alpha. This is not handled by
+# Skia's software blending code. Consequently, this test is random on
+# basic-layers when using skia. See bug 1004483.
+fuzzy(1,65536) random-if(B2G) fuzzy-if(Android,9,65536) random-if(Android&&AndroidVersion<15) random-if(skiaContent&&!layersGPUAccelerated) == webgl-color-alpha-test.html?colorVal=1.0&alphaVal=0.5&alpha&premult  wrapper.html?colors-half-alpha.png
 
 
 # Check for hanging framebuffer bindings:
diff --git a/layout/tools/reftest/reftest.js b/layout/tools/reftest/reftest.js
index 8acc57784f90..9734b9a5b739 100644
--- a/layout/tools/reftest/reftest.js
+++ b/layout/tools/reftest/reftest.js
@@ -625,6 +625,7 @@ function BuildConditionSandbox(aURL) {
     var info = gfxInfo.getInfo();
     sandbox.azureQuartz = info.AzureCanvasBackend == "quartz";
     sandbox.azureSkia = info.AzureCanvasBackend == "skia";
+    sandbox.skiaContent = info.AzureContentBackend == "skia";
     sandbox.azureSkiaGL = info.AzureSkiaAccelerated; // FIXME: assumes GL right now
     // true if we are using the same Azure backend for rendering canvas and content
     sandbox.contentSameGfxBackendAsCanvas = info.AzureContentBackend == info.AzureCanvasBackend