Index: uspace/lib/cpp/include/impl/type_traits.hpp
===================================================================
--- uspace/lib/cpp/include/impl/type_traits.hpp	(revision d504700202ed70c0ffbf69eb0f4a6fb1546b8866)
+++ uspace/lib/cpp/include/impl/type_traits.hpp	(revision 28cb784349e6a16ac5f6aaadf65e2eb00ba0c94d)
@@ -945,4 +945,8 @@
 
     template<>
+    struct make_signed<char>: aux::type_is<signed char>
+    { /* DUMMY BODY */ };
+
+    template<>
     struct make_signed<unsigned char>: aux::type_is<signed char>
     { /* DUMMY BODY */ };
@@ -966,4 +970,8 @@
     template<class T>
     struct make_unsigned: aux::type_is<T>
+    { /* DUMMY BODY */ };
+
+    template<>
+    struct make_unsigned<char>: aux::type_is<unsigned char>
     { /* DUMMY BODY */ };