diff --git a/bin/tests/system/tkey/ns1/named.conf.in b/bin/tests/system/tkey/ns1/named.conf.in
index 50600b7..b0f1700 100644
--- a/bin/tests/system/tkey/ns1/named.conf.in
+++ b/bin/tests/system/tkey/ns1/named.conf.in
@@ -32,6 +32,7 @@ options {
 	tkey-domain "server";
 	tkey-dhkey "server" KEYID;
 	allow-query-cache { any; };
+	random-device "/dev/urandom";
 };
 
 key rndc_key {