diff --git a/zerver/tests/test_auth_backends.py b/zerver/tests/test_auth_backends.py
index 65de88d026..204c1bae54 100644
--- a/zerver/tests/test_auth_backends.py
+++ b/zerver/tests/test_auth_backends.py
@@ -282,7 +282,10 @@ class AuthBackendTest(ZulipTestCase):
     def test_devauth_backend(self):
         # type: () -> None
         self.verify_backend(DevAuthBackend(),
-                            good_kwargs=dict(dev_auth_username=self.get_username()))
+                            good_kwargs=dict(dev_auth_username=self.get_username(),
+                                             realm=get_realm("zulip")),
+                            bad_kwargs=dict(dev_auth_username=self.get_username(),
+                                            realm=get_realm("invalid")))
 
     @override_settings(AUTHENTICATION_BACKENDS=('zproject.backends.ZulipRemoteUserBackend',))
     def test_remote_user_backend(self):
diff --git a/zerver/views/auth.py b/zerver/views/auth.py
index d525b836d9..64b983c5f8 100644
--- a/zerver/views/auth.py
+++ b/zerver/views/auth.py
@@ -586,7 +586,7 @@ def dev_direct_login(request, **kwargs):
     email = request.POST['direct_email']
     subdomain = get_subdomain(request)
     realm = get_realm(subdomain)
-    user_profile = authenticate(dev_auth_username=email, realm_subdomain=realm.subdomain)
+    user_profile = authenticate(dev_auth_username=email, realm=realm)
     if user_profile is None:
         raise Exception("User cannot login")
     do_login(request, user_profile)
@@ -615,7 +615,7 @@ def api_dev_fetch_api_key(request, username=REQ()):
 
     return_data = {}  # type: Dict[str, bool]
     user_profile = authenticate(dev_auth_username=username,
-                                realm_subdomain=realm.subdomain,
+                                realm=realm,
                                 return_data=return_data)
     if return_data.get("inactive_realm"):
         return json_error(_("Your realm has been deactivated."),
diff --git a/zerver/views/email_log.py b/zerver/views/email_log.py
index 7e0db38ceb..1b015fbb78 100755
--- a/zerver/views/email_log.py
+++ b/zerver/views/email_log.py
@@ -67,7 +67,7 @@ def generate_all_emails(request):
     assert result.status_code == 302
 
     # New login email
-    logged_in = client.login(dev_auth_username=registered_email)
+    logged_in = client.login(dev_auth_username=registered_email, realm=realm)
     assert logged_in
 
     # New user invite and reminder emails
diff --git a/zproject/backends.py b/zproject/backends.py
index 467505c440..93ecf22f40 100644
--- a/zproject/backends.py
+++ b/zproject/backends.py
@@ -533,14 +533,17 @@ class ZulipLDAPUserPopulator(ZulipLDAPAuthBackendBase):
 class DevAuthBackend(ZulipAuthMixin):
     # Allow logging in as any user without a password.
     # This is used for convenience when developing Zulip.
-    def authenticate(self, dev_auth_username: Optional[str]=None, realm_subdomain: Optional[str]=None,
+    def authenticate(self, dev_auth_username: Optional[str]=None, realm: Optional[Realm]=None,
                      return_data: Optional[Dict[str, Any]]=None) -> Optional[UserProfile]:
         assert dev_auth_username is not None
+        if realm is None:
+            return None
         user_profile = common_get_active_user_by_email(dev_auth_username, return_data=return_data)
         if user_profile is None:
             return None
-        if not dev_auth_enabled(user_profile.realm):
+        if not dev_auth_enabled(realm):
             return None
+        assert realm == user_profile.realm
         return user_profile
 
 class GitHubAuthBackend(SocialAuthMixin, GithubOAuth2):