diff --git a/include/utl/impl/crtp.h b/include/utl/helper/crtp.h
old mode 100755
new mode 100644
similarity index 95%
rename from include/utl/impl/crtp.h
rename to include/utl/helper/crtp.h
index 9258a87..fde5d77
--- a/include/utl/impl/crtp.h
+++ b/include/utl/helper/crtp.h
@@ -21,7 +21,7 @@
 #ifndef __utl_impl_crtp_h__
 #define __utl_impl_crtp_h__
 
-#include <utl/impl/version.h>
+#include <utl/impl/impl.h>
 
 /*!
  * \defgroup crtp   CRTP idiom support header
diff --git a/include/utl/impl/concepts.h b/include/utl/impl/concepts.h
index b597c05..361c6fd 100755
--- a/include/utl/impl/concepts.h
+++ b/include/utl/impl/concepts.h
@@ -21,8 +21,6 @@
 #ifndef __utl_impl_concepts_h__
 #define __utl_impl_concepts_h__
 
-#include <utl/impl/version.h>
-
 /*!
  * utl inner concept preprecessor flag
  * \defgroup crtp
diff --git a/include/utl/impl/impl.h b/include/utl/impl/impl.h
new file mode 100644
index 0000000..8346a52
--- /dev/null
+++ b/include/utl/impl/impl.h
@@ -0,0 +1,34 @@
+/*!
+ * \file   /utl/impl/impl.h
+ * \brief  Implementation detail main header
+ *
+ * Copyright (C) 2018 Christos Choutouridis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifndef __utl_impl_impl_h__
+#define __utl_impl_impl_h__
+
+
+// Include implementation details once
+#include <utl/impl/version.h>
+#include <utl/impl/concepts.h>
+#include <utl/impl/types.h>
+
+// STL dependency
+#include <type_traits>
+
+
+#endif /* __utl_impl_impl_h__ */
diff --git a/include/utl/impl/types.h b/include/utl/impl/types.h
new file mode 100644
index 0000000..8f614ba
--- /dev/null
+++ b/include/utl/impl/types.h
@@ -0,0 +1,32 @@
+/*!
+ * \file   /utl/impl/types.h
+ * \brief  Basic type alias support
+ *
+ * Copyright (C) 2018 Christos Choutouridis
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation, either version 3
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+#ifndef __utl_impl_types_h__
+#define __utl_impl_types_h__
+
+#include <stdint.h>
+
+
+typedef uint8_t  byte_t;         /*!< 8 bits wide */
+typedef uint16_t word_t;         /*!< 16 bits wide */
+typedef uint32_t dword_t;        /*!< 32 bits wide */
+
+
+#endif /* __utl_impl_types_h__ */
diff --git a/include/utl/impl/version.h b/include/utl/impl/version.h
index a15b6f5..f7a6f91 100755
--- a/include/utl/impl/version.h
+++ b/include/utl/impl/version.h
@@ -18,8 +18,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-#ifndef __utl_impl_crtp_h__
-#define __utl_impl_crtp_h__
+#ifndef __utl_impl_version_h__
+#define __utl_impl_version_h__
 
 //!\defgroup version version
 //! Definitions of the utl version
@@ -37,4 +37,4 @@
 #error "Sorry. uTL requires C++11"
 #endif
 
-#endif /* __utl_impl_crtp_h__ */
+#endif /* __utl_impl_version_h__ */