1 files changed, 1 insertions, 0 deletions

diff --git a/src/6to4.c b/src/6to4.c
index 5e75223a..b66ef5cc 100644
--- a/src/6to4.c
+++ b/src/6to4.c
@@ -24,6 +24,7 @@
 #include <config.h>
 #endif
 
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/socket.h>