diff --git a/tests/funcs/test_harm_funcs.py b/tests/funcs/test_harm_funcs.py
index e09177a01c7c8ee83c1eae8fba5aaba7737d106f..052d5f8daf7c818d66bbcf9c3b6870e6ef616b5b 100644
--- a/tests/funcs/test_harm_funcs.py
+++ b/tests/funcs/test_harm_funcs.py
@@ -134,8 +134,8 @@ def test_harmSingleVarIntermediateFlagging(data, reshaper):
             raise NotImplementedError('untested test case')
 
         assert all(flagger[field].iloc[start:end] > UNFLAGGED)
-        assert all(~flagger[field].iloc[:start] == UNFLAGGED)
-        assert all(~flagger[field].iloc[end:] == UNFLAGGED)
+        assert all(flagger[field].iloc[:start] == UNFLAGGED)
+        assert all(flagger[field].iloc[end:] == UNFLAGGED)
 
     elif 'shift' in reshaper:
         if reshaper == "nshift":