diff --git a/include/boost/config/stdlib/stlport.hpp b/include/boost/config/stdlib/stlport.hpp
index 98fdd434..b1dabf23 100644
--- a/include/boost/config/stdlib/stlport.hpp
+++ b/include/boost/config/stdlib/stlport.hpp
@@ -98,8 +98,10 @@
 //
 // We always have SGI style hash_set, hash_map, and slist:
 //
+#ifndef _STLP_NO_EXTENSIONS
 #define BOOST_HAS_HASH
 #define BOOST_HAS_SLIST
+#endif
 
 //
 // STLport does a good job of importing names into namespace std::,