diff --git a/modules/gfx/src/shader/fraglight_vs.glsl b/modules/gfx/src/shader/fraglight_vs.glsl
index 3eb7006e76c0874ffd26a66581b0b4dd6f7c1d5c..9b1856d12cd8920f0b87e7306385377f0b6237a4 100644
--- a/modules/gfx/src/shader/fraglight_vs.glsl
+++ b/modules/gfx/src/shader/fraglight_vs.glsl
@@ -21,7 +21,7 @@ void main()
     // ambient occlusion and color terms
     ambient_color = gl_MultiTexCoord0;
   } else {
-    ambient_color.rgb = gl_Color;
+    ambient_color.rgb = gl_Color.rgb;
     ambient_color.a = 1.0;
   }
   gl_FrontColor=gl_Color;