diff --git a/Image.cpp b/Image.cpp
index c84df37..dc6eacc 100644
--- a/Image.cpp
+++ b/Image.cpp
@@ -19,7 +19,7 @@
 
 static inline int color2int(Color c)
 {
-	u8 a = 255 - c.a;
+	u8 a = (255 - c.a) * gdAlphaMax / 255;
 	return (a << 24) | (c.r << 16) | (c.g << 8) | c.b;
 }
 
@@ -31,7 +31,7 @@ static inline Color int2color(int c)
 	c2.g = (c >> 8) & 0xff;
 	c2.r = (c >> 16) & 0xff;
 	a = (c >> 24) & 0xff;
-	c2.a = 255 - a;
+	c2.a = 255 - (a*255 / gdAlphaMax);
 	return c2;
 }