Index: msgpack-1.3.0/include/msgpack/adaptor/int.hpp
===================================================================
--- msgpack-1.3.0.orig/include/msgpack/adaptor/int.hpp
+++ msgpack-1.3.0/include/msgpack/adaptor/int.hpp
@@ -70,13 +70,17 @@ namespace detail {
     template <>
     struct object_char_sign<true> {
         static inline void make(msgpack::object& o, char v) {
-            if (v < 0) {
+            // Since char is unsigned on ARM, the condition below
+            // always evaluates to true and causes error if
+            // -Werror=type-limits is enabled.
+            int v2 = v;
+            if (v2 < 0) {
                 o.type = msgpack::type::NEGATIVE_INTEGER;
-                o.via.i64 = v;
+                o.via.i64 = v2;
             }
             else {
                 o.type = msgpack::type::POSITIVE_INTEGER;
-                o.via.u64 = v;
+                o.via.u64 = v2;
             }
         }
     };