diff --git a/src/java.desktop/macosx/native/libawt_lwawt/font/CGGlyphImages.m b/src/java.desktop/macosx/native/libawt_lwawt/font/CGGlyphImages.m
index 67c6573..b7c11df 100644
--- a/src/java.desktop/macosx/native/libawt_lwawt/font/CGGlyphImages.m
+++ b/src/java.desktop/macosx/native/libawt_lwawt/font/CGGlyphImages.m
@@ -282,7 +282,13 @@
 static inline UInt8
 CGGI_ConvertBWPixelToByteGray(UInt32 p)
 {
-    return 0xFF - (((p >> 24 & 0xFF) + (p >> 16 & 0xFF) + (p >> 8 & 0xFF)) / 3);
+    UInt8* lut = getReverseGammaLut();
+
+    UInt8 r = lut[0xFF - (p >> 24 & 0xFF)];
+    UInt8 g = lut[0xFF - (p >> 16 & 0xFF)];
+    UInt8 b = lut[0xFF - (p >>  8 & 0xFF)];
+
+    return ((r + g + b) / 3);
 }
 
 static void