diff --git a/source/testbench.sv b/source/testbench.sv
index 1872eed..6f27f84 100644
--- a/source/testbench.sv
+++ b/source/testbench.sv
@@ -32,7 +32,7 @@ module testbench #(parameter CPU_COUNT = 1024)
 
         initial begin
             reset = 1'b1;
-            repeat($urandom % 5 + 2) @(posedge clock);
+            repeat($unsigned($random) % 5 + 2) @(posedge clock);
             reset = 1'b0;
             @(posedge clock);