diff --git a/Makefile b/Makefile
index 19894b6e..ca0952be 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-CPPFLAGS=-std=c++11 -I./include -Wall -Werror -g 
+CPPFLAGS=-std=c++11 -I./include -Wall -Werror -g -Wextra
 CXX=g++
 COVERAGE_OUTPUT=out
 
diff --git a/include/cereal/details/traits.hpp b/include/cereal/details/traits.hpp
index ccf3cc58..7512be53 100644
--- a/include/cereal/details/traits.hpp
+++ b/include/cereal/details/traits.hpp
@@ -508,7 +508,7 @@ namespace cereal
                      "  ar & a\n"
                      "  return new T(a);\n"
                      "}\n\n" );
-      static T * load_andor_allocate( A & ar )
+      static T * load_andor_allocate( A & )
       { return new T(); }
     };
 
diff --git a/include/cereal/external/rapidjson/genericstream.h b/include/cereal/external/rapidjson/genericstream.h
index 5cfab31f..0b283194 100644
--- a/include/cereal/external/rapidjson/genericstream.h
+++ b/include/cereal/external/rapidjson/genericstream.h
@@ -35,7 +35,7 @@ namespace rapidjson {
       }
 
       // Not implemented
-      void Put(Ch c)     { RAPIDJSON_ASSERT(false); }
+      void Put(Ch)       { RAPIDJSON_ASSERT(false); }
       void Flush()       { RAPIDJSON_ASSERT(false); }
       Ch* PutBegin()     { RAPIDJSON_ASSERT(false); return 0; }
       size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
diff --git a/include/cereal/external/rapidjson/reader.h b/include/cereal/external/rapidjson/reader.h
index d2d95bbc..6e706c7b 100644
--- a/include/cereal/external/rapidjson/reader.h
+++ b/include/cereal/external/rapidjson/reader.h
@@ -418,7 +418,7 @@ private:
 #else
   template<class Ch>
   typename std::enable_if < std::numeric_limits<Ch>::max() < 265, bool>::type
-    characterOk( Ch c )
+    characterOk( Ch )
   {
     return true;
   }
diff --git a/include/cereal/external/rapidjson/writer.h b/include/cereal/external/rapidjson/writer.h
index 17a89c90..1a1e7b30 100644
--- a/include/cereal/external/rapidjson/writer.h
+++ b/include/cereal/external/rapidjson/writer.h
@@ -193,7 +193,7 @@ protected:
 #else
   template<class Ch>
   typename std::enable_if < std::numeric_limits<Ch>::max() < 265, bool>::type
-    characterOk( Ch c )
+    characterOk( Ch )
   {
     return true;
   }
diff --git a/include/cereal/external/rapidxml/rapidxml_print.hpp b/include/cereal/external/rapidxml/rapidxml_print.hpp
index ce6a320d..f890d410 100644
--- a/include/cereal/external/rapidxml/rapidxml_print.hpp
+++ b/include/cereal/external/rapidxml/rapidxml_print.hpp
@@ -116,7 +116,7 @@ namespace rapidxml
 
         // Print attributes of the node
         template<class OutIt, class Ch>
-        inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int flags)
+        inline OutIt print_attributes(OutIt out, const xml_node<Ch> *node, int /*flags*/)
         {
             for (xml_attribute<Ch> *attribute = node->first_attribute(); attribute; attribute = attribute->next_attribute())
             {
diff --git a/performance.cpp b/performance.cpp
index 8b5e10b9..30340f24 100644
--- a/performance.cpp
+++ b/performance.cpp
@@ -148,7 +148,14 @@ void test( std::string const & name,
             DataTCereal const & dataC,
             DataTBoost const & dataB,
             size_t numAverages = 100,
-            bool validateData = false )
+            bool validateData = false );
+
+template <class SerializationT, class DataTCereal, class DataTBoost>
+void test( std::string const & name,
+            DataTCereal const & dataC,
+            DataTBoost const & dataB,
+            size_t numAverages,
+            bool /*validateData*/ )
 {
   std::cout << "-----------------------------------" << std::endl;
   std::cout << "Running test: " << name << std::endl;
@@ -293,7 +300,7 @@ struct PoDStructBoost
   double d;
 
   template <class Archive>
-  void serialize( Archive & ar, const unsigned int version )
+  void serialize( Archive & ar, const unsigned int /*version*/ )
   {
     ar & a & b & c & d;
   };
@@ -321,7 +328,7 @@ struct PoDChildBoost : virtual PoDStructBoost
   std::vector<float> v;
 
   template <class Archive>
-  void serialize( Archive & ar, const unsigned int version )
+  void serialize( Archive & ar, const unsigned int /*version*/ )
   {
     ar & boost::serialization::base_object<PoDStructBoost>(*this);
     ar & v;
diff --git a/sandbox.cpp b/sandbox.cpp
index 92d155f8..8c9b9496 100644
--- a/sandbox.cpp
+++ b/sandbox.cpp
@@ -394,7 +394,7 @@ class BoostTransitionMS
     int x;
 
     template <class Archive>
-    void serialize( Archive & ar, const std::uint32_t version )
+    void serialize( Archive & ar, const std::uint32_t /*version*/ )
     { ar( x ); }
 };
 
@@ -412,11 +412,11 @@ class BoostTransitionSplit
     int x;
 
     template <class Archive>
-    void save( Archive & ar, const std::uint32_t version ) const
+    void save( Archive & ar, const std::uint32_t /*version*/ ) const
     { ar( x ); }
 
     template <class Archive>
-    void load( Archive & ar, const std::uint32_t version )
+    void load( Archive & ar, const std::uint32_t /*version*/ )
     { ar( x ); }
 };