diff --git a/src/libCom/fdmgr/fdManager.cpp b/src/libCom/fdmgr/fdManager.cpp
index b031a7b27..a9533bf76 100644
--- a/src/libCom/fdmgr/fdManager.cpp
+++ b/src/libCom/fdmgr/fdManager.cpp
@@ -21,6 +21,7 @@
 // 1) This library is not thread safe
 //
 
+#undef FD_SETSIZE
 #define FD_SETSIZE 4096
 
 //