diff --git a/standards/application/waku-api.md b/standards/application/waku-api.md
index 6e9c32e..16cbbbd 100644
--- a/standards/application/waku-api.md
+++ b/standards/application/waku-api.md
@@ -495,7 +495,7 @@ functions:
         type: Array<string>
         description: "The content topics for the node to subscribe to."
     returns:
-        type: void
+        type: result<void, error>
 
   unsubscribe:
     description: "Unsubscribe from specific content topics"