diff --git a/hive/server/condenser_api/methods.py b/hive/server/condenser_api/methods.py
index 2021ae4bf340be46e2999795ddfb33cf7db3f96f..ae9a6473cd782d7393fbf12c3a05fac27c47bc89 100644
--- a/hive/server/condenser_api/methods.py
+++ b/hive/server/condenser_api/methods.py
@@ -184,6 +184,7 @@ async def get_posts_by_given_sort(context, sort: str, start_author: str = '', st
     start_permlink  = valid_permlink(start_permlink, allow_empty=True),
     limit           = valid_limit(limit, 100, 20),
     tag             = valid_tag(tag, allow_empty=True)
+    observer        = valid_account(observer, allow_empty=True)
 
     posts = []
     is_community = tag[:5] == 'hive-'