diff --git a/src/invidious/routes/api/v1/authentication.cr b/src/invidious/routes/api/v1/authentication.cr
index 8d8f909d..3923fb00 100644
--- a/src/invidious/routes/api/v1/authentication.cr
+++ b/src/invidious/routes/api/v1/authentication.cr
@@ -111,7 +111,7 @@ module Invidious::Routes::API::V1::Authentication
           answer = Digest::MD5.hexdigest(answer.downcase.strip)
 
           if tokens.empty?
-            return error_template(500, "Erroneous CAPTCHA")
+            return error_json(500, "Erroneous CAPTCHA")
           end
 
           found_valid_captcha = false