diff --git a/include/common/defaults.h b/include/common/defaults.h
index cdc6b7f..9d65f9c 100644
--- a/include/common/defaults.h
+++ b/include/common/defaults.h
@@ -143,8 +143,11 @@
  * command-line '-n' argument.
  */
 #ifndef SYSTEM_MAXCONN
+#ifndef DEFAULT_MAXCONN
 #define DEFAULT_MAXCONN 2000
+#endif
 #else
+#undef  DEFAULT_MAXCONN
 #define DEFAULT_MAXCONN SYSTEM_MAXCONN
 #endif