diff --git a/test/unit/ntp_core.c b/test/unit/ntp_core.c
index c977a78..ac01205 100644
--- a/test/unit/ntp_core.c
+++ b/test/unit/ntp_core.c
@@ -334,10 +334,8 @@ test_unit(void)
   CPS_ParseNTPSourceAdd(source_line, &source);
 
   for (i = 0; i < 1000; i++) {
-    if (random() % 2)
-      source.params.interleaved = 1;
-    if (random() % 2)
-      source.params.authkey = get_random_key_id();
+    source.params.interleaved = random() % 2;
+    source.params.authkey = random() % 2 ? get_random_key_id() : INACTIVE_AUTHKEY;
     source.params.version = random() % 4 + 1;
 
     UTI_ZeroTimespec(&current_time);