diff --git a/tap_zendesk/streams.py b/tap_zendesk/streams.py
index 1305f02..bddf837 100644
--- a/tap_zendesk/streams.py
+++ b/tap_zendesk/streams.py
@@ -574,6 +574,7 @@ def sync(self, state):
 class AgentsActivity(Stream):
     name = "agents_activity"
     replication_method = "FULL_TABLE"
+    key_properties = ["agent_id"]
 
     def sync(self, state): # pylint: disable=unused-argument