diff --git a/libraries/pbrlib/genosl/mx_roughness_dual.osl b/libraries/pbrlib/genosl/mx_roughness_dual.osl
index 98d62ee13e..6de64c73ad 100644
--- a/libraries/pbrlib/genosl/mx_roughness_dual.osl
+++ b/libraries/pbrlib/genosl/mx_roughness_dual.osl
@@ -1,9 +1,5 @@
 void mx_roughness_dual(vector2 roughness, output vector2 result)
 {
-    if (roughness.y < 0.0)
-    {
-        roughness.y = roughness.x;
-    }
     result.x = clamp(roughness.x * roughness.x, M_FLOAT_EPS, 1.0);
     if (roughness.y < 0.0)
     {