diff --git a/ctis/instruments/_instruments_test.py b/ctis/instruments/_instruments_test.py
index f35717d..7c6480d 100644
--- a/ctis/instruments/_instruments_test.py
+++ b/ctis/instruments/_instruments_test.py
@@ -22,9 +22,9 @@ def test_deproject(self, a: ctis.instruments.AbstractInstrument):
             project=lambda x: x,
             deproject=lambda x: x,
         )
-    ]
+    ],
 )
 class TestInstrument(
-    abc.ABC,
+    AbstractTestAbstractInstrument,
 ):
     pass