diff --git a/lib/getdef.c b/lib/getdef.c
index bea28129..a181cc2b 100644
--- a/lib/getdef.c
+++ b/lib/getdef.c
@@ -148,6 +148,7 @@ static struct itemdef knowndef_table[] = {
 #ifdef USE_PAM
 	PAMDEFS
 #endif
+	{NULL, NULL}
 };
 
 #ifndef LOGINDEFS