build BUGFIX when both SSH and TLS are off
diff --git a/src/io.c b/src/io.c
index 3653b6c..432ec70 100644
--- a/src/io.c
+++ b/src/io.c
@@ -25,6 +25,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <poll.h>
+#include <inttypes.h>
 #include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>