--- a/layout/painting/nsCSSRenderingGradients.cpp
+++ b/layout/painting/nsCSSRenderingGradients.cpp
@@ -1019,20 +1019,21 @@ nsCSSGradientRenderer::BuildWebRenderPar
                                                 LayoutDevicePoint& aLineEnd,
                                                 LayoutDeviceSize& aGradientRadius)
 {
   bool isRepeat = mGradient->mRepeating || mForceRepeatToCoverTiles;
   aMode = isRepeat ? WrGradientExtendMode::Repeat : WrGradientExtendMode::Clamp;
 
   aStops.SetLength(mStops.Length());
   for(uint32_t i = 0; i < mStops.Length(); i++) {
-    aStops[i].color.r = mStops[i].mColor.r;
-    aStops[i].color.g = mStops[i].mColor.g;
-    aStops[i].color.b = mStops[i].mColor.b;
-    aStops[i].color.a = mStops[i].mColor.a * aOpacity;
+    float alpha = mStops[i].mColor.a * aOpacity;
+    aStops[i].color.r = mStops[i].mColor.r * alpha;
+    aStops[i].color.g = mStops[i].mColor.g * alpha;
+    aStops[i].color.b = mStops[i].mColor.b * alpha;
+    aStops[i].color.a = alpha;
     aStops[i].offset = mStops[i].mPosition;
   }
 
   aLineStart = LayoutDevicePoint(mLineStart.x, mLineStart.y);
   aLineEnd = LayoutDevicePoint(mLineEnd.x, mLineEnd.y);
   aGradientRadius = LayoutDeviceSize(mRadiusX, mRadiusY);
 }