diff --git a/CMakeLists.txt b/CMakeLists.txt
index e4d6793..07810da 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,7 +6,7 @@ cmake_minimum_required (VERSION 2.8.11)
 project (cpp-jwt)
 
 #SET (CMAKE_CXX_COMPILER /usr/local/bin/g++)
-SET( CMAKE_CXX_FLAGS  "-std=c++14 -Wall" )
+SET( CMAKE_CXX_FLAGS  "-std=c++14 -Wall -Wextra" )
 
 include_directories (include)
 
diff --git a/include/jwt/base64.hpp b/include/jwt/base64.hpp
index 226c1f0..4cb28d7 100644
--- a/include/jwt/base64.hpp
+++ b/include/jwt/base64.hpp
@@ -229,16 +229,16 @@ inline std::string base64_decode(const char* in, size_t len)
     const auto fourth = dmap.at(in[3]);
     result[i + 2] = (third << 6) | fourth;
     bytes_wr++;
-    //FALLTHROUGH
   }
+  //FALLTHROUGH
   case 3:
   {
     const auto second = dmap.at(in[1]);
     const auto third  = dmap.at(in[2]);
     result[i + 1] = (second << 4) | (third >> 2);
     bytes_wr++;
-    //FALLTHROUGH
   }
+  //FALLTHROUGH
   case 2:
   {
     const auto first  = dmap.at(in[0]);
diff --git a/include/jwt/impl/jwt.ipp b/include/jwt/impl/jwt.ipp
index 197a614..01b0881 100644
--- a/include/jwt/impl/jwt.ipp
+++ b/include/jwt/impl/jwt.ipp
@@ -607,6 +607,7 @@ void jwt_object::set_decode_params(DecodeParams& dparams, params::detail::valida
 template <typename DecodeParams>
 void jwt_object::set_decode_params(DecodeParams& dparams)
 {
+  (void) dparams; // prevent -Wunused-parameter with gcc
   return;
 }