diff --git a/lib/log.h b/lib/log.h
index 1466e3becf..e09d747ee2 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -171,6 +171,7 @@ extern void zlog_backtrace_sigsafe(int priority, void *program_counter);
    It caches the most recent localtime result and can therefore
    avoid multiple calls within the same second.  If buflen is too small,
    *buf will be set to '\0', and 0 will be returned. */
+#define QUAGGA_TIMESTAMP_LEN 40
 extern size_t quagga_timestamp(int timestamp_precision /* # subsecond digits */,
 			       char *buf, size_t buflen);
 
@@ -181,7 +182,7 @@ struct timestamp_control {
    size_t len;		/* length of rendered timestamp */
    int precision;	/* configuration parameter */
    int already_rendered; /* should be initialized to 0 */
-   char buf[40];	/* will contain the rendered timestamp */
+   char buf[QUAGGA_TIMESTAMP_LEN];	/* will contain the rendered timestamp */
 };
 
 /* Defines for use in command construction: */
diff --git a/lib/vty.c b/lib/vty.c
index ae3e595364..13b8b3019f 100644
--- a/lib/vty.c
+++ b/lib/vty.c
@@ -208,7 +208,7 @@ vty_log_out (struct vty *vty, const char *level, const char *proto_str,
 void
 vty_time_print (struct vty *vty, int cr)
 {
-  char buf [25];
+  char buf[QUAGGA_TIMESTAMP_LEN];
   
   if (quagga_timestamp(0, buf, sizeof(buf)) == 0)
     {