diff --git a/app/auth/routes.py b/app/auth/routes.py
index 1ca6a631..c09a9be7 100644
--- a/app/auth/routes.py
+++ b/app/auth/routes.py
@@ -88,6 +88,9 @@ def register():
     if current_user.is_authenticated:
         return redirect(url_for('main.index'))
     form = RegistrationForm()
+    # Recaptcha is optional
+    if not current_app.config['RECAPTCHA_PUBLIC_KEY'] or not current_app.config['RECAPTCHA_PRIVATE_KEY']:
+        del form.recaptcha
     if g.site.registration_mode != 'RequireApplication':
         form.question.validators = ()
     if form.validate_on_submit():
diff --git a/config.py b/config.py
index cb39d944..7dbe2cc4 100644
--- a/config.py
+++ b/config.py
@@ -19,8 +19,8 @@ class Config(object):
     MAIL_FROM = os.environ.get('MAIL_FROM') or None
     MAIL_ERRORS = os.environ.get('MAIL_ERRORS') is not None
     ADMINS = os.environ.get('ADMINS')
-    RECAPTCHA_PUBLIC_KEY = os.environ.get("RECAPTCHA_PUBLIC_KEY")
-    RECAPTCHA_PRIVATE_KEY = os.environ.get("RECAPTCHA_PRIVATE_KEY")
+    RECAPTCHA_PUBLIC_KEY = os.environ.get("RECAPTCHA_PUBLIC_KEY") or None
+    RECAPTCHA_PRIVATE_KEY = os.environ.get("RECAPTCHA_PRIVATE_KEY") or None
     MODE = os.environ.get('MODE') or 'development'
     LANGUAGES = ['de', 'en']
     FULL_AP_CONTEXT = bool(int(os.environ.get('FULL_AP_CONTEXT', 0)))