diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 127d9fd..31d9614 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -13,7 +13,7 @@ env:
 
 jobs:
   build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     services:
       postgres:
diff --git a/.github/workflows/pypi-release.yml b/.github/workflows/pypi-release.yml
index 9585730..e535322 100644
--- a/.github/workflows/pypi-release.yml
+++ b/.github/workflows/pypi-release.yml
@@ -21,7 +21,7 @@ on:
 jobs:
   build-pypi-distribs:
     name: Build and publish library to PyPI
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v3
diff --git a/federatedcode/settings.py b/federatedcode/settings.py
index 07d36e5..c1cfc25 100644
--- a/federatedcode/settings.py
+++ b/federatedcode/settings.py
@@ -61,9 +61,13 @@
 FEDERATEDCODE_CLIENT_ID = env.str("FEDERATEDCODE_CLIENT_ID")
 FEDERATEDCODE_CLIENT_SECRET = env.str("FEDERATEDCODE_CLIENT_SECRET")
 
-RECAPTCHA_PUBLIC_KEY = env.str("RECAPTCHA_PUBLIC_KEY", "")
-RECAPTCHA_PRIVATE_KEY = env.str("RECAPTCHA_PRIVATE_KEY", "")
-SILENCED_SYSTEM_CHECKS = ["captcha.recaptcha_test_key_error"]
+if env.str("RECAPTCHA_PUBLIC_KEY", None):
+    RECAPTCHA_PUBLIC_KEY = env.str("RECAPTCHA_PUBLIC_KEY")
+
+if env.str("RECAPTCHA_PRIVATE_KEY", None):
+    RECAPTCHA_PRIVATE_KEY = env.str("RECAPTCHA_PRIVATE_KEY")
+
+SILENCED_SYSTEM_CHECKS = ["django_recaptcha.recaptcha_test_key_error"]
 RECAPTCHA_DOMAIN = env.str("RECAPTCHA_DOMAIN", "www.recaptcha.net")
 
 # Application definition