diff --git a/system/utest/evil/evil.c b/system/utest/evil/evil.c
index 4e48edd..75493e4 100644
--- a/system/utest/evil/evil.c
+++ b/system/utest/evil/evil.c
@@ -103,7 +103,9 @@
 } info_t;
 
 int rnum(int m) {
-    return (random() & 0x7FFFFFFFU) % m;
+    uint32_t data;
+    zx_cprng_draw((void*)&data, sizeof(data));
+    return (data & 0x7FFFFFFFU) % m;
 }
 
 void* blaster(void* arg) {