diff --git a/test/unit_test/static/chrono_test.cpp b/test/unit_test/static/chrono_test.cpp
index e3027b57..39d4da58 100644
--- a/test/unit_test/static/chrono_test.cpp
+++ b/test/unit_test/static/chrono_test.cpp
@@ -33,14 +33,14 @@ using namespace std::chrono_literals;
 
 
 // construction
-static_assert(std::constructible_from<si::time<si::second, std::int64_t>, std::chrono::seconds>);
-static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::second, std::int64_t>>);
-static_assert(std::constructible_from<si::time<si::hour, std::int64_t>, std::chrono::hours>);
-static_assert(!std::convertible_to<std::chrono::hours, si::time<si::hour, std::int64_t>>);
-static_assert(!std::constructible_from<si::time<si::second, std::int64_t>, std::chrono::hours>);
-static_assert(!std::convertible_to<std::chrono::hours, si::time<si::second, std::int64_t>>);
-static_assert(!std::constructible_from<si::time<si::hour, std::int64_t>, std::chrono::seconds>);
-static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::hour, std::int64_t>>);
+static_assert(std::constructible_from<si::time<si::second, std::chrono::seconds::rep>, std::chrono::seconds>);
+static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::second, std::chrono::seconds::rep>>);
+static_assert(std::constructible_from<si::time<si::hour, std::chrono::hours::rep>, std::chrono::hours>);
+static_assert(!std::convertible_to<std::chrono::hours, si::time<si::hour, std::chrono::hours::rep>>);
+static_assert(!std::constructible_from<si::time<si::second, std::chrono::hours::rep>, std::chrono::hours>);
+static_assert(!std::convertible_to<std::chrono::hours, si::time<si::second, std::chrono::hours::rep>>);
+static_assert(!std::constructible_from<si::time<si::hour, std::chrono::seconds::rep>, std::chrono::seconds>);
+static_assert(!std::convertible_to<std::chrono::seconds, si::time<si::hour, std::chrono::seconds::rep>>);
 
 // CTAD
 static_assert(std::is_same_v<decltype(quantity{1s}), si::time<si::second, std::chrono::seconds::rep>>);