diff --git a/tests/test_pdfinfo.py b/tests/test_pdfinfo.py
index 1a21e0e0..1aa75a86 100644
--- a/tests/test_pdfinfo.py
+++ b/tests/test_pdfinfo.py
@@ -173,17 +173,15 @@ def test_stack_abuse():
     p = pikepdf.Pdf.new()
 
     stream = pikepdf.Stream(p, b'q ' * 35)
-    with pytest.warns(None) as record:
+    with pytest.warns(UserWarning, match="overflowed"):
         pdfinfo.info._interpret_contents(stream)
-    assert 'overflowed' in str(record[0].message)
 
     stream = pikepdf.Stream(p, b'q Q Q Q Q')
-    with pytest.warns(None) as record:
+    with pytest.warns(UserWarning, match="underflowed") as record:
         pdfinfo.info._interpret_contents(stream)
-    assert 'underflowed' in str(record[0].message)
 
     stream = pikepdf.Stream(p, b'q ' * 135)
-    with pytest.warns(None):
+    with pytest.warns():
         with pytest.raises(RuntimeError):
             pdfinfo.info._interpret_contents(stream)