diff --git a/log.c b/log.c
index fa26eb4c..ecb9698a 100644
--- a/log.c
+++ b/log.c
@@ -22,6 +22,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <vis.h>
 
 #include "tmux.h"
 
@@ -66,19 +67,24 @@ log_close(void)
 void
 log_vwrite(const char *msg, va_list ap)
 {
-	char		*fmt;
+	char		*fmt, *out;
 	struct timeval	 tv;
 
 	if (log_file == NULL)
 		return;
 
-	gettimeofday(&tv, NULL);
-	if (asprintf(&fmt, "%lld.%06d %s\n", (long long)tv.tv_sec,
-	    (int)tv.tv_usec, msg) == -1)
+	if (vasprintf(&fmt, msg, ap) == -1)
 		exit(1);
-	if (vfprintf(log_file, fmt, ap) == -1)
+	if (stravis(&out, fmt, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL) == -1)
+		exit(1);
+
+	gettimeofday(&tv, NULL);
+	if (fprintf(log_file, "%lld.%06d %s\n", (long long)tv.tv_sec,
+	    (int)tv.tv_usec, out) == -1)
 		exit(1);
 	fflush(log_file);
+
+	free(out);
 	free(fmt);
 }