diff --git a/src/eth_dma_wrapper.sv b/src/eth_dma_wrapper.sv
index 9e832be..52b0bfd 100644
--- a/src/eth_dma_wrapper.sv
+++ b/src/eth_dma_wrapper.sv
@@ -91,7 +91,11 @@ assign apb_mac_ctrl_stub.penable = '0;
 
 
 taxi_eth_mac_25g_us #(
-    .SIM(`SIM),
+`ifdef SIM
+    .SIM('1),
+`else
+    .SIM('0),
+`endif
     .VENDOR("XILINX"),
     .FAMILY("kintexuplus"),
     .CNT(2),