diff --git a/test/unit/test_result_iteration.cxx b/test/unit/test_result_iteration.cxx
index ff444e28b..495ff1eff 100644
--- a/test/unit/test_result_iteration.cxx
+++ b/test/unit/test_result_iteration.cxx
@@ -12,7 +12,9 @@ void test_result_iteration()
   pqxx::connection cx;
   pqxx::work tx{cx};
   pqxx::result r{tx.exec("SELECT generate_series(1, 3)")};
+#if defined(PQXX_HAVE_CONCEPTS)
   static_assert(std::forward_iterator<decltype(r.begin())>);
+#endif
 
   PQXX_CHECK(std::end(r) != std::begin(r), "Broken begin/end.");
   PQXX_CHECK(std::rend(r) != std::rbegin(r), "Broken rbegin/rend.");
diff --git a/test/unit/test_row.cxx b/test/unit/test_row.cxx
index 7beaa5f03..378375efe 100644
--- a/test/unit/test_row.cxx
+++ b/test/unit/test_row.cxx
@@ -11,7 +11,9 @@ void test_row()
   pqxx::connection cx;
   pqxx::work tx{cx};
   pqxx::row r{tx.exec("SELECT 1, 2, 3").one_row()};
+#if defined(PQXX_HAVE_CONCEPTS)
   static_assert(std::forward_iterator<decltype(r.begin())>);
+#endif
   PQXX_CHECK_EQUAL(std::size(r), 3, "Unexpected row size.");
   PQXX_CHECK_EQUAL(r.at(0).as<int>(), 1, "Wrong value at index 0.");
   PQXX_CHECK(std::begin(r) != std::end(r), "Broken row iteration.");