diff --git a/bin/wsim b/bin/wsim
index 740193e0f..9defcc1c9 100755
--- a/bin/wsim
+++ b/bin/wsim
@@ -78,7 +78,7 @@ def elfFileCheck(args):
 def prepSim(args, ElfFile):
     flags = ""
     if args.vcd:
-        args.args += " -DMAKEVCD=1"
+        args.params += " MAKE_VCD=1 "
     if args.rvvi:
         args.params += " RVVI_SYNTH_SUPPORTED=1 "
     if args.tb == "testbench_fp":
diff --git a/testbench/testbench.sv b/testbench/testbench.sv
index c777fdf3f..40f5410ef 100644
--- a/testbench/testbench.sv
+++ b/testbench/testbench.sv
@@ -44,6 +44,7 @@ module testbench;
   parameter I_CACHE_ADDR_LOGGER=0;
   parameter D_CACHE_ADDR_LOGGER=0;
   parameter RVVI_SYNTH_SUPPORTED=0;
+  parameter MAKE_VCD=0;
 
   `ifdef USE_IMPERAS_DV
     import idvPkg::*;
@@ -230,10 +231,10 @@ module testbench;
       end
       $finish;
     end
-`ifdef MAKEVCD
-    $dumpfile("testbench.vcd");
-    $dumpvars;
-`endif
+    if (MAKE_VCD) begin
+      $dumpfile("testbench.vcd");
+      $dumpvars;
+    end
   end // initial begin
 
   // Model the testbench as an fsm.