diff --git a/testing/test_helpconfig.py b/testing/test_helpconfig.py
index 6eecbfd37..41fa953ad 100644
--- a/testing/test_helpconfig.py
+++ b/testing/test_helpconfig.py
@@ -33,7 +33,7 @@ def test_hookvalidation_unknown(testdir):
     """)
     result = testdir.runpytest()
     assert result.ret != 0
-    result.stderr.fnmatch_lines([
+    result.stdout.fnmatch_lines([
         '*unknown hook*pytest_hello*'
     ])