diff --git a/changelog.d/5555.bugfix b/changelog.d/5555.bugfix
new file mode 100644
index 000000000000..c0b1ecf81aa0
--- /dev/null
+++ b/changelog.d/5555.bugfix
@@ -0,0 +1 @@
+Fixed m.login.jwt using unregistred user_id and added pyjwt>=1.6.4 as jwt conditional dependencies. Contributed by Pau Rodriguez-Estivill.
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index 13698d963837..6324c00ef184 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -95,6 +95,7 @@
     "url_preview": ["lxml>=3.5.0"],
     "test": ["mock>=2.0", "parameterized"],
     "sentry": ["sentry-sdk>=0.7.2"],
+    "jwt": ["pyjwt>=1.6.4"],
 }
 
 ALL_OPTIONAL_REQUIREMENTS = set()
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 4efb679a042a..ede6bc8b1eae 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -336,7 +336,7 @@ def do_jwt_login(self, login_submission):
             }
         else:
             user_id, access_token = (
-                yield self.handlers.registration_handler.register(localpart=user)
+                yield self.registration_handler.register(localpart=user)
             )
 
             device_id = login_submission.get("device_id")