diff --git a/include/gl.h b/include/gl.h
index ec78f20..5828171 100644
--- a/include/gl.h
+++ b/include/gl.h
@@ -112,10 +112,9 @@ __BEGIN_DECLS
 
 /* Texture Environment */
 #define GL_TEXTURE_ENV_MODE 0x2200
-#define GL_REPLACE          0x0
-#define GL_MODULATE         0x1
-#define GL_DECAL            0x2
-#define GL_MODULATEALPHA    0x3
+#define GL_REPLACE          0x1E01
+#define GL_MODULATE         0x2100
+#define GL_DECAL            0x2101
 
 /* TextureMagFilter */
 #define GL_NEAREST                      0x2600