diff --git a/roles/custom/matrix-dendrite/defaults/main.yml b/roles/custom/matrix-dendrite/defaults/main.yml
index a60c33d26..a4ab6104c 100644
--- a/roles/custom/matrix-dendrite/defaults/main.yml
+++ b/roles/custom/matrix-dendrite/defaults/main.yml
@@ -101,6 +101,9 @@ matrix_dendrite_enable_registration_captcha: false
 matrix_dendrite_recaptcha_public_key: ""
 matrix_dendrite_recaptcha_private_key: ""
 matrix_dendrite_recaptcha_siteverify_api: "https://www.google.com/recaptcha/api/siteverify"
+matrix_dendrite_recaptcha_api_js_url: ""
+matrix_dendrite_recaptcha_form_field: ""
+matrix_dendrite_recaptcha_sitekey_class: ""
 
 # A list of additional "volumes" to mount in the container.
 # This list gets populated dynamically based on Dendrite extensions that have been enabled.
diff --git a/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2 b/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
index 65cb4c2c3..e3ed3685f 100644
--- a/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
+++ b/roles/custom/matrix-dendrite/templates/dendrite/dendrite.yaml.j2
@@ -193,6 +193,9 @@ client_api:
   recaptcha_private_key: {{ matrix_dendrite_recaptcha_private_key|to_json }}
   recaptcha_bypass_secret: ""
   recaptcha_siteverify_api: {{ matrix_dendrite_recaptcha_siteverify_api|to_json }}
+  recaptcha_api_js_url: ""
+  recaptcha_form_field: ""
+  recaptcha_sitekey_class: ""
 
   # TURN server information that this homeserver should send to clients.
   turn: