diff --git a/modules/gfx/src/shader/fraglight_lf_vs.glsl b/modules/gfx/src/shader/fraglight_lf_vs.glsl
index be5b64918b29e308fa85594f3b3a6f5490cfcc85..011fb782053ecc1f5a65a11658c6099304e8ad9e 100644
--- a/modules/gfx/src/shader/fraglight_lf_vs.glsl
+++ b/modules/gfx/src/shader/fraglight_lf_vs.glsl
@@ -18,7 +18,7 @@ void main()
     // ambient occlusion and color terms
     ambient_color = gl_MultiTexCoord0;
   } else {
-    ambient_color.rgb = gl_Color;
+    ambient_color = gl_Color;
     ambient_color.a = 1.0;
   }
   gl_FrontColor=gl_Color;