diff --git a/gfx/thebes/public/gfxColor.h b/gfx/thebes/public/gfxColor.h
index 8585332956b0..54b9a4bccc73 100644
--- a/gfx/thebes/public/gfxColor.h
+++ b/gfx/thebes/public/gfxColor.h
@@ -56,6 +56,7 @@
     #define GFX_NTOHL(x) _byteswap_ulong(x)
     #define GFX_HAVE_CHEAP_NTOHL
   #else
+    #include "prbit.h"
     // A reasonably fast generic little-endian implementation.
     #define GFX_NTOHL(x) \
          ( (PR_ROTATE_RIGHT32((x),8) & 0xFF00FF00) | \