diff --git a/res/raw/dot_vs.glsl b/res/raw/dot_vs.glsl
index e4ebeed..9cf3c74 100644
--- a/res/raw/dot_vs.glsl
+++ b/res/raw/dot_vs.glsl
@@ -2,7 +2,7 @@
 
 void main() {
     vec4 objPos = vec4(ATTRIB_position, 1.0);
-    float tmpPointSize = objPos.z*7.0;
+    float tmpPointSize = ATTRIB_position.z*7.0;
     pointSize = 0.5-tmpPointSize/1000.0;
     objPos.z = 0.0;
     objPos.x = objPos.x - ATTRIB_offsetX * tmpPointSize/100.0;