diff --git a/vncviewer/vncviewer.cxx b/vncviewer/vncviewer.cxx
index 4c7e212..6fea199 100644
--- a/vncviewer/vncviewer.cxx
+++ b/vncviewer/vncviewer.cxx
@@ -18,6 +18,10 @@
  * USA.
  */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>