diff --git a/sloth/annotations/model.py b/sloth/annotations/model.py
index 6c0aff7..9ef56da 100644
--- a/sloth/annotations/model.py
+++ b/sloth/annotations/model.py
@@ -999,7 +999,7 @@ def interpolateRange(self):
             for l in range(len(lann)):
                 if lann[l]['type'] == fann[i]['type'] and lann[l]['class'] == fann[i]['class']:
                     lannIdx = l
-            if lannIdx == None:
+            if lannIdx is None:
                 LOG.error("Error: could not find matching label, skipping")
                 continue
 
diff --git a/sloth/gui/labeltool.py b/sloth/gui/labeltool.py
index 29f2fc1..1341d46 100644
--- a/sloth/gui/labeltool.py
+++ b/sloth/gui/labeltool.py
@@ -129,7 +129,7 @@ def onCurrentImageChanged(self):
 
         img = self.labeltool.getImage(new_image)
 
-        if img == None:
+        if img is None:
             self.controls.setFilename("")
             self.selectionmodel.setCurrentIndex(new_image.index(), QItemSelectionModel.ClearAndSelect|QItemSelectionModel.Rows)
             return