diff --git a/tmate-session.c b/tmate-session.c
index 62493278..5ba0896c 100644
--- a/tmate-session.c
+++ b/tmate-session.c
@@ -5,6 +5,7 @@
 #include <netinet/in.h>
 #include <sys/socket.h>
 
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/tmate-ssh-client.c b/tmate-ssh-client.c
index c52c166c..42c4e6a6 100644
--- a/tmate-ssh-client.c
+++ b/tmate-ssh-client.c
@@ -1,6 +1,7 @@
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <event.h>