diff --git a/src/ClientFile.cxx b/src/ClientFile.cxx
index ca5acb229..dccf0a327 100644
--- a/src/ClientFile.cxx
+++ b/src/ClientFile.cxx
@@ -17,6 +17,7 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
+#include "config.h"
 #include "ClientFile.hxx"
 #include "Client.hxx"
 #include "ack.h"