diff --git a/test/test_date.mojo b/test/test_date.mojo
index e51bd2a..edf695b 100644
--- a/test/test_date.mojo
+++ b/test/test_date.mojo
@@ -64,7 +64,7 @@ def test_epoch() raises:
 
 def test_writable_roundtrip() raises:
     var d = parse_date("2026-07-03T01:02:03-07:00")
-    assert_equal(String.write(d), "2026-07-03T01:02:03-07:00")
+    assert_equal(String(d), "2026-07-03T01:02:03-07:00")
 
 
 def test_item_date_method() raises:
diff --git a/test/test_errors.mojo b/test/test_errors.mojo
index fe0944d..4d622df 100644
--- a/test/test_errors.mojo
+++ b/test/test_errors.mojo
@@ -12,7 +12,7 @@ def _assert_lc(source: String, offset: Int, line: Int, col: Int) raises:
 
 
 def _msg(e: Error) -> String:
-    return String.write(e)
+    return String(e)
 
 
 # --------------------------------------------------------------------------