diff --git a/include/matjson.hpp b/include/matjson.hpp
index be4bb48..ec88216 100644
--- a/include/matjson.hpp
+++ b/include/matjson.hpp
@@ -73,7 +73,7 @@ namespace matjson {
     };
     template <class T>
     concept CanDeserialize = requires(matjson::Value const& value, T t) {
-        { Serialize<std::remove_cvref_t<T>>::fromJson(value) };
+        { Serialize<std::remove_cvref_t<T>>::fromJson(value) } -> geode::impl::IsResult<>;
     };
     template <class T>
     concept CanSerde = CanSerialize<T> && CanDeserialize<T>;