diff --git a/files/templates/sign_up.html b/files/templates/sign_up.html
index fbdaf874f..4f42182c0 100644
--- a/files/templates/sign_up.html
+++ b/files/templates/sign_up.html
@@ -108,7 +108,7 @@
 												</div>
 
 												{% if hcaptcha %}
-													<div class="h-captcha" data-sitekey="{{hcaptcha}}"></div>
+													<div class="h-captcha" data-sitekey="{{hcaptcha}}" data-theme="dark"></div>
 												{% endif %}
 
 												<button class="btn btn-primary login w-100 mt-3" id="register_button">Register</button>