diff --git boost/spirit/home/classic/core/composite/no_actions.hpp boost/spirit/home/classic/core/composite/no_actions.hpp
index 638a297..60386cf 100644
--- boost/spirit/home/classic/core/composite/no_actions.hpp
+++ boost/spirit/home/classic/core/composite/no_actions.hpp
@@ -38,10 +38,10 @@ struct no_actions_action_policy:
     template<typename ActorT, typename AttrT, typename IteratorT>
     void
     do_action(
-        ActorT const&       actor,
-        AttrT&              val,
-        IteratorT const&    first,
-        IteratorT const&    last) const
+        ActorT const&,
+        AttrT&,
+        IteratorT const&,
+        IteratorT const&) const
     {}
 };
 
diff --git boost/spirit/home/classic/core/non_terminal/impl/grammar.ipp boost/spirit/home/classic/core/non_terminal/impl/grammar.ipp
index 3b25b3d..957b853 100644
--- boost/spirit/home/classic/core/non_terminal/impl/grammar.ipp
+++ boost/spirit/home/classic/core/non_terminal/impl/grammar.ipp
@@ -83,7 +83,7 @@ struct grammar_definition
         {   // Does _not_ copy the helpers member !
         }
 
-        grammar_helper_list& operator=(grammar_helper_list const& x)
+        grammar_helper_list& operator=(grammar_helper_list const&)
         {   // Does _not_ copy the helpers member !
             return *this;
         }
diff --git boost/spirit/home/classic/meta/impl/refactoring.ipp boost/spirit/home/classic/meta/impl/refactoring.ipp
index 61cc6b5..af7ec11 100644
--- boost/spirit/home/classic/meta/impl/refactoring.ipp
+++ boost/spirit/home/classic/meta/impl/refactoring.ipp
@@ -324,7 +324,7 @@ namespace impl {
         >
         static typename parser_result<ParserT, ScannerT>::type
         parse(ParserT const &, ScannerT const& scan, ActionT const &action,
-            NestedT const& nested_d)
+            NestedT const&)
         {
             return action.parse(scan);
         }
diff --git boost/spirit/home/classic/phoenix/tuples.hpp boost/spirit/home/classic/phoenix/tuples.hpp
index 50cec6b..9cbdde9 100644
--- boost/spirit/home/classic/phoenix/tuples.hpp
+++ boost/spirit/home/classic/phoenix/tuples.hpp
@@ -211,7 +211,7 @@ struct tuple_element
     typedef nil_t& rtype;
     typedef nil_t const& crtype;
 
-    static nil_t    get(TupleT const& t)    { return nil_t(); }
+    static nil_t    get(TupleT const&)    { return nil_t(); }
 };
 
 //////////////////////////////////
diff --git boost/spirit/home/classic/utility/impl/chset.ipp boost/spirit/home/classic/utility/impl/chset.ipp
index 3017035..dd7fc2e 100644
--- boost/spirit/home/classic/utility/impl/chset.ipp
+++ boost/spirit/home/classic/utility/impl/chset.ipp
@@ -129,7 +129,7 @@ inline chset<CharT>::chset(anychar_parser /*arg*/)
 }
 
 template <typename CharT>
-inline chset<CharT>::chset(nothing_parser arg_)
+inline chset<CharT>::chset(nothing_parser)
 : ptr(new basic_chset<CharT>()) {}
 
 template <typename CharT>
@@ -182,7 +182,7 @@ chset<CharT>::operator=(CharT rhs)
 
 template <typename CharT>
 inline chset<CharT>&
-chset<CharT>::operator=(anychar_parser rhs)
+chset<CharT>::operator=(anychar_parser)
 {
     utility::impl::detach_clear(ptr);
     ptr->set(
@@ -194,7 +194,7 @@ chset<CharT>::operator=(anychar_parser rhs)
 
 template <typename CharT>
 inline chset<CharT>&
-chset<CharT>::operator=(nothing_parser rhs)
+chset<CharT>::operator=(nothing_parser)
 {
     utility::impl::detach_clear(ptr);
     return *this;