diff --git a/include/boost/utf8_codecvt_facet.hpp b/include/boost/utf8_codecvt_facet.hpp
index 663d65b..c05ca77 100644
--- a/include/boost/utf8_codecvt_facet.hpp
+++ b/include/boost/utf8_codecvt_facet.hpp
@@ -52,14 +52,14 @@
 
 namespace std{ 
     #if defined(__COMO__)
-		using ::mbstate_t;
+        using ::mbstate_t;
     #elif defined(BOOST_MSVC)
-		using ::mbstate_t;
+        using ::mbstate_t;
     #elif defined(BOOST_INTEL)
         using ::mbstate_t;
     #elif defined(BOOST_NO_STDC_NAMESPACE)
         using ::codecvt;
-		using ::mbstate_t;
+        using ::mbstate_t;
     #endif
 } // namespace std