diff --git a/planet/subscription_request.py b/planet/subscription_request.py
index 26b761e0..212bdc7c 100644
--- a/planet/subscription_request.py
+++ b/planet/subscription_request.py
@@ -133,7 +133,7 @@ def catalog_source(
     parameters = {
         "item_types": item_types,
         "asset_types": asset_types,
-        "geometry": geometry,
+        "geometry": geojson.as_geom(geometry),
     }
 
     try:
diff --git a/tests/unit/test_subscription_request.py b/tests/unit/test_subscription_request.py
index 51e75903..7c0bca22 100644
--- a/tests/unit/test_subscription_request.py
+++ b/tests/unit/test_subscription_request.py
@@ -90,6 +90,30 @@ def test_catalog_source_success(geom_geojson):
     assert res == expected
 
 
+def test_catalog_source_featurecollection(featurecollection_geojson,
+                                          geom_geojson):
+    '''geojson specified as featurecollection is simplified down to just
+    the geometry'''
+    res = subscription_request.catalog_source(
+        item_types=["PSScene"],
+        asset_types=["ortho_analytic_4b"],
+        geometry=featurecollection_geojson,
+        start_time=datetime(2021, 3, 1),
+    )
+
+    expected = {
+        "type": "catalog",
+        "parameters": {
+            "geometry": geom_geojson,
+            "start_time": "2021-03-01T00:00:00Z",
+            "item_types": ["PSScene"],
+            "asset_types": ["ortho_analytic_4b"]
+        }
+    }
+
+    assert res == expected
+
+
 def test_catalog_source_invalid_start_time(geom_geojson):
     with pytest.raises(exceptions.ClientError):
         subscription_request.catalog_source(