diff --git a/plugins/PostProcessingPlugin/tests/TestPostProcessingPlugin.py b/plugins/PostProcessingPlugin/tests/TestPostProcessingPlugin.py
index a5ef9e47c9..2c9a25fcac 100644
--- a/plugins/PostProcessingPlugin/tests/TestPostProcessingPlugin.py
+++ b/plugins/PostProcessingPlugin/tests/TestPostProcessingPlugin.py
@@ -18,30 +18,29 @@ sys.path.append(os.path.join(os.path.dirname(os.path.abspath(__file__)), ".."))
 def test_community_user_script_allowed():
     assert PostProcessingPlugin._isScriptAllowed("blaat.py")
 
+
 # noinspection PyProtectedMember
 @patch("cura.ApplicationMetadata.IsEnterpriseVersion", False)
 def test_community_bundled_script_allowed():
     assert PostProcessingPlugin._isScriptAllowed(_bundled_file_path())
 
+
 # noinspection PyProtectedMember
 @patch("cura.ApplicationMetadata.IsEnterpriseVersion", True)
 def test_enterprise_unsigned_user_script_not_allowed():
     assert not PostProcessingPlugin._isScriptAllowed("blaat.py")
 
+
 # noinspection PyProtectedMember
 @patch("cura.ApplicationMetadata.IsEnterpriseVersion", True)
 def test_enterprise_signed_user_script_allowed():
     mocked_trust = MagicMock()
     mocked_trust.signedFileCheck = MagicMock(return_value=True)
 
-    realSignatureFileExistsFor = Trust.signatureFileExistsFor
-    Trust.signatureFileExistsFor = MagicMock(return_value=True)
+    with patch.object(Trust, "signatureFileExistsFor", return_value = True):
+        with patch("UM.Trust.Trust.getInstanceOrNone", return_value=mocked_trust):
+            assert PostProcessingPlugin._isScriptAllowed("blaat.py")
 
-    with patch("UM.Trust.Trust.getInstanceOrNone", return_value=mocked_trust):
-        assert PostProcessingPlugin._isScriptAllowed("blaat.py")
-
-    # cleanup
-    Trust.signatureFileExistsFor = realSignatureFileExistsFor
 
 # noinspection PyProtectedMember
 @patch("cura.ApplicationMetadata.IsEnterpriseVersion", False)