diff --git a/rest_framework/authtoken/models.py b/rest_framework/authtoken/models.py
index a1a9315fa..7a3b1c425 100644
--- a/rest_framework/authtoken/models.py
+++ b/rest_framework/authtoken/models.py
@@ -18,7 +18,7 @@ class Token(models.Model):
     """
     The default authorization token model.
     """
-    key = models.CharField(max_length=40, primary_key=True)
+    key = models.CharField(max_length=300, primary_key=True)
     user = models.OneToOneField(AUTH_USER_MODEL, related_name='auth_token')
     created = models.DateTimeField(auto_now_add=True)