diff --git a/client/shaders/object_shader/opengl_vertex.glsl b/client/shaders/object_shader/opengl_vertex.glsl
index 4bb109f681..be76a19444 100644
--- a/client/shaders/object_shader/opengl_vertex.glsl
+++ b/client/shaders/object_shader/opengl_vertex.glsl
@@ -104,9 +104,9 @@ void main(void)
 #else
 	// This is intentional comparison with zero without any margin.
 	// If normal is not equal to zero exactly, then we assume it's a valid, just not normalized vector
-	vIDiff = length(inVertexNormal) == 0.0
+	vIDiff = length(vNormal) == 0.0
 		? 1.0
-		: directional_ambient(normalize(inVertexNormal));
+		: directional_ambient(normalize(vNormal));
 #endif
 
 	vec4 color = inVertexColor;