diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index 9889282e..84985391 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -9,12 +9,21 @@ on:
 jobs:
   build:
     name: build
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
+      fail-fast: false
       matrix:
-        python-version: ["3.7", "3.8", "3.9"]
+        python-version:
+          - "3.7"
+          - "3.8"
+          - "3.9"
+          - "3.10"
+#          - "3.11-dev"
+        os:
+          - ubuntu-latest
+#          - windows-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v3
diff --git a/pystac_client/item_search.py b/pystac_client/item_search.py
index 9b57b78a..e2d179dd 100644
--- a/pystac_client/item_search.py
+++ b/pystac_client/item_search.py
@@ -22,11 +22,10 @@
                             r"(?P<remainder>(T|t)\d{2}:\d{2}:\d{2}(\.\d+)?"
                             r"(?P<tz_info>Z|([-+])(\d{2}):(\d{2}))?)?)?)?")
 
-
-class GeoInterface(Protocol):
-    def __geo_interface__(self) -> dict:
-        ...
-
+# todo: add runtime_checkable when we drop 3.7 support
+# class GeoInterface(Protocol):
+#     def __geo_interface__(self) -> dict:
+#         ...
 
 DatetimeOrTimestamp = Optional[Union[datetime_, str]]
 Datetime = Union[Tuple[str], Tuple[str, str]]
@@ -43,7 +42,8 @@ def __geo_interface__(self) -> dict:
 IDsLike = Union[IDs, str, List[str], Iterator[str]]
 
 Intersects = dict
-IntersectsLike = Union[str, Intersects, GeoInterface]
+IntersectsLike = Union[str, object, Intersects]
+# todo: after 3.7 is dropped, replace object with GeoInterface
 
 Query = dict
 QueryLike = Union[Query, List[str]]
diff --git a/tests/test_item_search.py b/tests/test_item_search.py
index 49f66aba..a347b1ba 100644
--- a/tests/test_item_search.py
+++ b/tests/test_item_search.py
@@ -264,6 +264,10 @@ def test_intersects_non_geo_interface_object(self):
         with pytest.raises(Exception):
             ItemSearch(url=SEARCH_URL, intersects=object())
 
+    def test_intersects_non_geo_interface_object(self):
+        with pytest.raises(Exception):
+            ItemSearch(url=SEARCH_URL, intersects=object())
+
     def test_filter_lang_default_for_dict(self):
         search = ItemSearch(url=SEARCH_URL, filter={})
         assert search.get_parameters()['filter-lang'] == 'cql2-json'