diff --git a/tap_hubspot_beta/streams.py b/tap_hubspot_beta/streams.py
index db19347..06a972c 100644
--- a/tap_hubspot_beta/streams.py
+++ b/tap_hubspot_beta/streams.py
@@ -904,11 +904,17 @@ class ListMembershipV3Stream(hubspotV3Stream):
     path = "crm/v3/lists/{list_id}/memberships"
     records_jsonpath = "$[*]"
     parent_stream_type = ListSearchV3Stream
+    primary_keys = ["list_id"]
 
     schema = th.PropertiesList(
         th.Property("results", th.CustomType({"type": ["array", "string"]})),
+        th.Property("list_id", th.IntegerType),
     ).to_dict()
 
+    def post_process(self, row, context):
+        row = super().post_process(row, context)
+        row["list_id"] = context["list_id"]
+        return row
 
 
 class AssociationDealsStream(hubspotV4Stream):