diff --git a/src/sw/redis++/shards.cpp b/src/sw/redis++/shards.cpp
index fc58eea..ea57266 100644
--- a/src/sw/redis++/shards.cpp
+++ b/src/sw/redis++/shards.cpp
@@ -42,7 +42,7 @@ std::pair<Slot, Node> RedirectionError::_parse_error(const std::string &msg) con
         auto host = msg.substr(space_pos + 1, colon_pos - space_pos - 1);
         auto port = std::stoi(msg.substr(colon_pos + 1));
 
-        return {slot, {host, port}};
+        return {static_cast<std::size_t>(slot), {host, port}};
     } catch (const std::exception &) {
         throw ProtoError("invalid redirection error message: " + msg);
     }