diff --git a/include/boost/fusion/algorithm/transformation/pop_back.hpp b/include/boost/fusion/algorithm/transformation/pop_back.hpp
index 29de95b3..6059c555 100644
--- a/include/boost/fusion/algorithm/transformation/pop_back.hpp
+++ b/include/boost/fusion/algorithm/transformation/pop_back.hpp
@@ -80,7 +80,7 @@ namespace boost { namespace fusion
         {};
 
 
-        template <typename Iterator, bool IsLast>
+        template <typename Iterator, bool IsLast_>
         struct prior_impl
         {
             typedef typename Iterator::iterator_base_type base_type;