diff --git a/gql_graph.go b/gql_graph.go
index 8461cc4..9067c7d 100644
--- a/gql_graph.go
+++ b/gql_graph.go
@@ -700,6 +700,9 @@ func GQLTypeSignalInput() *graphql.InputObject {
 
 func GQLSubscribeSignal(p graphql.ResolveParams) (interface{}, error) {
   return GQLSubscribeFn(p, func(signal GraphSignal, p graphql.ResolveParams)(interface{}, error) {
+    if signal == nil {
+      return nil, nil
+    }
     return signal, nil
   })
 }