diff --git a/init.c b/init.c
index 09bbce4..b5f9abc 100644
--- a/init.c
+++ b/init.c
@@ -274,6 +274,11 @@
 		return 1;
 	}
 
+	if (!o->timeout && o->time_based) {
+		log_err("fio: time_based requires a runtime/timeout setting\n");
+		o->time_based = 0;
+	}
+
 	return 0;
 }