diff --git a/include/tts/tools/types.hpp b/include/tts/tools/types.hpp
index 4422a19..fc08a40 100644
--- a/include/tts/tools/types.hpp
+++ b/include/tts/tools/types.hpp
@@ -47,7 +47,7 @@ namespace tts
   /// List of all standard unsigned types.
   using uint_types        = types < std::uint64_t , std::uint32_t , std::uint16_t , std::uint8_t>;
   /// List of all standard integer types.
-  using integral_types    = concatenate_t<int_types,int_types>;
+  using integral_types    = concatenate_t<int_types,uint_types>;
   /// List of all standard arithmetic types.
   using arithmetic_types  = concatenate_t<real_types,int_types,uint_types>;
 }
diff --git a/standalone/tts/tts.hpp b/standalone/tts/tts.hpp
index 9417235..11c5a41 100644
--- a/standalone/tts/tts.hpp
+++ b/standalone/tts/tts.hpp
@@ -437,7 +437,7 @@ namespace tts
   using int_types         = types < std::int64_t , std::int32_t , std::int16_t , std::int8_t>;
   using signed_types      = concatenate_t<real_types,int_types>;
   using uint_types        = types < std::uint64_t , std::uint32_t , std::uint16_t , std::uint8_t>;
-  using integral_types    = concatenate_t<int_types,int_types>;
+  using integral_types    = concatenate_t<int_types,uint_types>;
   using arithmetic_types  = concatenate_t<real_types,int_types,uint_types>;
 }
 #include <tuple>