diff --git a/appservice.py b/appservice.py
index 781e0d0..a78a19c 100644
--- a/appservice.py
+++ b/appservice.py
@@ -459,7 +459,7 @@ def create_room(channel, user):
 def new_matrix_user(username):
     matrix_api = MatrixHttpApi(app.config['MATRIX_HOST'],
         token=app.config['MATRIX_AS_TOKEN'])
-    data = {'type': 'm.login.application_service','user': app.config['MATRIX_PNUT_PREFIX'] + username}
+    data = {'type': 'm.login.application_service','username': app.config['MATRIX_PNUT_PREFIX'] + username}
     try:
         matrix_api.register(content=data)
 
diff --git a/pnut-matrix.py b/pnut-matrix.py
index 6690c06..993f821 100644
--- a/pnut-matrix.py
+++ b/pnut-matrix.py
@@ -264,7 +264,7 @@ def new_matrix_user(username):
         token=config['MATRIX_AS_TOKEN'])
     data = {
         'type': 'm.login.application_service',
-        'user': config['MATRIX_PNUT_PREFIX'] + username
+        'username': config['MATRIX_PNUT_PREFIX'] + username
     }
     matrix_api.register(content=data)