diff --git a/contrib/ldapc++/src/SaslInteractionHandler.cpp b/contrib/ldapc++/src/SaslInteractionHandler.cpp
index c837226ef1..412b517a36 100644
--- a/contrib/ldapc++/src/SaslInteractionHandler.cpp
+++ b/contrib/ldapc++/src/SaslInteractionHandler.cpp
@@ -5,6 +5,7 @@
 
 #include <iostream>
 #include <iomanip>
+#include "config.h"
 
 #ifdef HAVE_TERMIOS_H
 #include <termios.h>