diff --git a/tests/test_trim.py b/tests/test_trim.py
index 6daca7c..a041bf5 100644
--- a/tests/test_trim.py
+++ b/tests/test_trim.py
@@ -30,15 +30,9 @@
     assert_greater_equal,
 )
 
-if sys.version_info >= (3, 7):
-    isascii = str.isascii  # pylint: disable=no-member
-else:
-    def isascii(s):
-        return re.fullmatch(r'[\0-\x7F]*', s) is not None
-
 def xlen(s):
     n = sum(1 if c else 0 for c in regex.split(r'(\X)', s))
-    if isascii(s):
+    if s.isascii():
         assert n == len(s)
     else:
         assert n <= len(s)