diff --git a/tests/unit/misc/test_lineparser.py b/tests/unit/misc/test_lineparser.py
index dcdb724cd..cd4a64274 100644
--- a/tests/unit/misc/test_lineparser.py
+++ b/tests/unit/misc/test_lineparser.py
@@ -114,7 +114,8 @@ class TestLineParser:
     def test_double_open(self, lineparser):
         """Test if save() bails on an already open file."""
         with lineparser._open('r'):
-            with pytest.raises(IOError):
+            with pytest.raises(IOError,
+                               match="Refusing to double-open LineParser."):
                 lineparser.save()
 
     def test_prepare_save(self, tmpdir, lineparser):