diff --git a/roles/matrix-synapse/templates/synapse/homeserver.yaml.j2 b/roles/matrix-synapse/templates/synapse/homeserver.yaml.j2
index 9f8dffaf..5eddfb6e 100644
--- a/roles/matrix-synapse/templates/synapse/homeserver.yaml.j2
+++ b/roles/matrix-synapse/templates/synapse/homeserver.yaml.j2
@@ -749,7 +749,7 @@ turn_shared_secret: {{ matrix_synapse_turn_shared_secret|string|to_json }}
 # connect to arbitrary endpoints without having first signed up for a
 # valid account (e.g. by passing a CAPTCHA).
 #
-turn_allow_guests: {{ matrix_synapse_turn_allow_guests }}
+turn_allow_guests: {{ matrix_synapse_turn_allow_guests|to_json }}
 
 
 ## Registration ##
@@ -854,7 +854,7 @@ registration_shared_secret: {{ matrix_synapse_registration_shared_secret|string|
 # participate in rooms hosted on this server which have been made
 # accessible to anonymous users.
 #
-allow_guest_access: {{ matrix_synapse_allow_guest_access }}
+allow_guest_access: {{ matrix_synapse_allow_guest_access|to_json }}
 
 # The identity server which we suggest that clients should use when users log
 # in on this server.