diff --git a/src/log.c b/src/log.c
index 5e1c35eb..c258b19b 100644
--- a/src/log.c
+++ b/src/log.c
@@ -87,12 +87,13 @@ void add_loglevel(const char *level) {
  *
  */
 void vlog(char *fmt, va_list args) {
-    char timebuf[64];
+    static char timebuf[64];
+    static struct tm result;
 
     /* Get current time */
     time_t t = time(NULL);
     /* Convert time to local time (determined by the locale) */
-    struct tm *tmp = localtime(&t);
+    struct tm *tmp = localtime_r(&t, &result);
     /* Generate time prefix */
     strftime(timebuf, sizeof(timebuf), "%x %X - ", tmp);
 #ifdef DEBUG_TIMING