diff --git a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
index 78ca4c695fb..80e4b8ccbef 100644
--- a/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
+++ b/mozilla/gfx/src/motif/nsDeviceContextUnix.cpp
@@ -244,7 +244,7 @@ PRUint32 nsDeviceContextUnix :: ConvertPixel(nscolor aColor)
   }
 
   if (mDepth == 24) {
-    newcolor = aColor;
+    newcolor = aColor & 0x00ffffff;
   }
   
   return (newcolor);