diff --git a/src/time/ctime.c b/src/time/ctime.c
index 185ec5543b958e04ff7560ae333ed7cac61a9c2c..36029315128f250a86264447ee20a95bd7f366b7 100644
--- a/src/time/ctime.c
+++ b/src/time/ctime.c
@@ -2,5 +2,7 @@
 
 char *ctime(const time_t *t)
 {
-	return asctime(localtime(t));
+	struct tm *tm = localtime(t);
+	if (!tm) return 0;
+	return asctime(tm);
 }