diff --git a/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.blackbox.v b/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.blackbox.v
index e636077..3e8b262 100644
--- a/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.blackbox.v
+++ b/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.blackbox.v
@@ -32,22 +32,22 @@
 
 (* blackbox *)
 module sky130_fd_sc_hvl__udp_mux_4to2 (
+    X ,
     A0,
     A1,
     A2,
     A3,
     S0,
-    S1,
-    X
+    S1
 );
 
+    output X ;
     input  A0;
     input  A1;
     input  A2;
     input  A3;
     input  S0;
     input  S1;
-    output X ;
 endmodule
 
 `default_nettype wire
diff --git a/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.v b/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.v
index 6579adc..764d1c1 100644
--- a/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.v
+++ b/models/udp_mux_4to2/sky130_fd_sc_hvl__udp_mux_4to2.v
@@ -34,22 +34,22 @@
 `include "./sky130_fd_sc_hvl__udp_mux_4to2.blackbox.v"
 `else
 primitive sky130_fd_sc_hvl__udp_mux_4to2 (
+    X ,
     A0,
     A1,
     A2,
     A3,
     S0,
-    S1,
-    X
+    S1
 );
 
+    output X ;
     input  A0;
     input  A1;
     input  A2;
     input  A3;
     input  S0;
     input  S1;
-    output X ;
 
     table
      //  A0  A1  A2  A3  S0  S1 :  X