diff --git a/include/fmt/base.h b/include/fmt/base.h
index 5acd3e6487078..772bc02ab9f07 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -1899,7 +1899,7 @@ template <typename Context> class basic_format_args {
       if (id < max_size()) arg = args_[id];
       return arg;
     }
-    if (id >= detail::max_packed_args) return arg;
+    if (static_cast<unsigned>(id) >= detail::max_packed_args) return arg;
     arg.type_ = type(id);
     if (arg.type_ == detail::type::none_type) return arg;
     arg.value_ = values_[id];