diff --git a/src/log.c b/src/log.c
index e6ab3c6..3035f88 100644
--- a/src/log.c
+++ b/src/log.c
@@ -7,7 +7,7 @@
 /* string equivalents to the severity values */
 static const char *severities[] = { "FATAL", "ERROR", "WARN ", "INFO ", "DEBUG" };
 
-static FILE *logfile = stdout;  /* log file pointer */
+static FILE *logfile = NULL;  /* log file pointer */
 
 void Log(int level, const char *format, ...)
 {
@@ -24,7 +24,7 @@ void Log(int level, const char *format, ...)
   gettimeofday(&tv, NULL);
   localtime_r(&(tv.tv_sec), &tm);
   strftime(timestamp, 32, "%F %T", &tm);
-  fprintf(logfile, "%s.%06u %s %s\n", timestamp, tv.tv_usec, severities[level], buf);
+  fprintf(logfile ? logfile : stdout, "%s.%06u %s %s\n", timestamp, tv.tv_usec, severities[level], buf);
 }
 
 void Log_assert_failed(const char *test, const char *file, int line)