diff --git a/koku/masu/api/sources/serializers.py b/koku/masu/api/sources/serializers.py
index 53da730c8c..1e52105e63 100644
--- a/koku/masu/api/sources/serializers.py
+++ b/koku/masu/api/sources/serializers.py
@@ -69,6 +69,7 @@ class Meta:
     setup_complete = serializers.BooleanField()
     created_timestamp = serializers.DateTimeField()
     data_updated_timestamp = serializers.DateTimeField()
+    polling_timestamp = serializers.DateTimeField(allow_null=True)
     active = serializers.BooleanField()
     paused = serializers.BooleanField()
     customer = CustomerSerializer()
diff --git a/koku/masu/api/sources/test/test_serializers.py b/koku/masu/api/sources/test/test_serializers.py
index d7a34df2ed..dc79fecf3e 100644
--- a/koku/masu/api/sources/test/test_serializers.py
+++ b/koku/masu/api/sources/test/test_serializers.py
@@ -47,7 +47,7 @@ def setUp(self):
     def test_serializer(self):
         """Test the serializer."""
         for entry in self.data:
-            provider = entry.get("provider")
+            provider: Provider = entry.get("provider")
             customer = provider.customer
             infrastructure = provider.infrastructure
 
@@ -61,6 +61,7 @@ def test_serializer(self):
                 "setup_complete": provider.setup_complete,
                 "created_timestamp": provider.created_timestamp,
                 "data_updated_timestamp": provider.data_updated_timestamp,
+                "polling_timestamp": provider.polling_timestamp,
                 "active": provider.active,
                 "paused": provider.paused,
                 "customer": validated_customer,