diff --git a/app/notifications/sns_cert_validator.py b/app/notifications/sns_cert_validator.py
index 1b3f7ea3d..c06d06c49 100644
--- a/app/notifications/sns_cert_validator.py
+++ b/app/notifications/sns_cert_validator.py
@@ -16,7 +16,7 @@ VALID_SNS_TOPICS = Config.VALID_SNS_TOPICS
 
 _signing_cert_cache = {}
 _cert_url_re = re.compile(
-    r'sns\.([a-z]{1,3}-[a-z]+-[0-9]{1,2})\.amazonaws\.com',
+    r'sns\.([a-z]{1,3}(?:-gov)?-[a-z]+-[0-9]{1,2})\.amazonaws\.com',
 )