diff --git a/app/lib/provider_discovery.rb b/app/lib/provider_discovery.rb
index abd98f3aa607c86a281b7668c7af74d8e5619808..3d0712a5ca6a0d99eb2ce0614cb60a285b59c06c 100644
--- a/app/lib/provider_discovery.rb
+++ b/app/lib/provider_discovery.rb
@@ -22,6 +22,7 @@ class ProviderDiscovery < OEmbed::ProviderDiscovery
         format ||= :xml if provider_endpoint
       end
 
+      raise OEmbed::NotFound, url if provider_endpoint.nil?
       begin
         provider_endpoint = Addressable::URI.parse(provider_endpoint)
         provider_endpoint.query = nil