diff --git a/colab/accounts/auth.py b/colab/accounts/auth.py
index 1a63968..9500fbd 100644
--- a/colab/accounts/auth.py
+++ b/colab/accounts/auth.py
@@ -14,7 +14,7 @@ class ColabBrowserIDBackend(BrowserIDBackend):
 
         user = self.User.objects.filter(emails__address=email)
 
-        if len(user) is not 0:
+        if not user:
             return user
 
         return self.User.objects.create_user(
diff --git a/colab/accounts/forms.py b/colab/accounts/forms.py
index c0d10b3..fcb6a75 100644
--- a/colab/accounts/forms.py
+++ b/colab/accounts/forms.py
@@ -58,7 +58,7 @@ class UserCreationForm(UserForm):
     def clean_username(self):
         username = self.cleaned_data['username']
         username = username.strip()
-        if len(username) is 0:
+        if not username:
             raise forms.ValidationError('This field should not be blank.')
         return username
 
--
libgit2 0.21.2