diff --git a/src/GEOMImpl/GEOMImpl_IPipe.hxx b/src/GEOMImpl/GEOMImpl_IPipe.hxx
index 5ed0050b9..4fdd314ff 100644
--- a/src/GEOMImpl/GEOMImpl_IPipe.hxx
+++ b/src/GEOMImpl/GEOMImpl_IPipe.hxx
@@ -19,6 +19,8 @@
 //
 //NOTE: This is an intreface to a function for the Pipe creation.
 
+#ifndef _GEOMImpl_IPIPE_HXX_
+#define _GEOMImpl_IPIPE_HXX_
 
 #include "GEOM_Function.hxx"
 
@@ -41,3 +43,5 @@ class GEOMImpl_IPipe
 
   Handle(GEOM_Function) _func;
 };
+
+#endif