diff --git a/adm_local/unix/config_files/check_Netgen.m4 b/adm_local/unix/config_files/check_Netgen.m4
index 24c81f037..680870f11 100644
--- a/adm_local/unix/config_files/check_Netgen.m4
+++ b/adm_local/unix/config_files/check_Netgen.m4
@@ -9,7 +9,7 @@ AC_LANG_SAVE
 AC_LANG_CPLUSPLUS
 
 AC_ARG_WITH(netgen,
-	    --with-netgen=DIR root directory path of NETGEN installation,
+	    [  --with-netgen=DIR root directory path of NETGEN installation],
 	    WITHNETGEN="yes",WITHNETGEN="no")
 
 NETGEN_INCLUDES=""
@@ -111,6 +111,7 @@ if test "x$Netgen_ok" = xno ; then
 else
   AC_MSG_RESULT(yes)
   NETGEN_LIBS="-lNETGEN"
+  CPPFLAGS="${CPPFLAGS} -DHAVE_NETGEN"
 fi
 fi
 AC_SUBST(NETGEN_INCLUDES)
diff --git a/idl/SMESH_BasicHypothesis.idl b/idl/SMESH_BasicHypothesis.idl
index c0251517f..f6a37655c 100644
--- a/idl/SMESH_BasicHypothesis.idl
+++ b/idl/SMESH_BasicHypothesis.idl
@@ -86,9 +86,12 @@ module SMESH
   {
   };
 
+#ifdef HAVE_NETGEN
   interface SMESH_NETGEN_3D : SMESH_3D_Algo
   {
   };
+#endif
+
 };
 
 #endif
diff --git a/src/SMESH_I/SMESH_HypothesisFactory_i.cxx b/src/SMESH_I/SMESH_HypothesisFactory_i.cxx
index ad363f06f..efb8134d5 100644
--- a/src/SMESH_I/SMESH_HypothesisFactory_i.cxx
+++ b/src/SMESH_I/SMESH_HypothesisFactory_i.cxx
@@ -26,7 +26,6 @@
 //  Module : SMESH
 //  $Header$
 
-using namespace std;
 using namespace std;
 #include "SMESH_HypothesisFactory_i.hxx"
 #include "SMESH_Hypothesis_i.hxx"
@@ -45,8 +44,9 @@ using namespace std;
 #include "SMESH_MEFISTO_2D_i.hxx"
 #include "SMESH_Quadrangle_2D_i.hxx"
 #include "SMESH_Hexa_3D_i.hxx"
+#ifdef HAVE_NETGEN
 #include "SMESH_NETGEN_3D_i.hxx"
-
+#endif
 //---------------------------------------
 
 //=============================================================================
@@ -92,8 +92,9 @@ _creatorMap["Regular_1D"] = new HypothesisCreator_i<SMESH_Regular_1D_i>;
 _creatorMap["MEFISTO_2D"] = new HypothesisCreator_i<SMESH_MEFISTO_2D_i>;
 _creatorMap["Quadrangle_2D"] = new HypothesisCreator_i<SMESH_Quadrangle_2D_i>;
 _creatorMap["Hexa_3D"] = new HypothesisCreator_i<SMESH_Hexa_3D_i>;
+#ifdef HAVE_NETGEN
 _creatorMap["NETGEN_3D"] = new HypothesisCreator_i<SMESH_NETGEN_3D_i>;
-
+#endif
 //---------------------------------------
 }