diff --git a/principalmapper/util/case_insensitive_dict.py b/principalmapper/util/case_insensitive_dict.py
index ff5ee90..f427fd3 100644
--- a/principalmapper/util/case_insensitive_dict.py
+++ b/principalmapper/util/case_insensitive_dict.py
@@ -31,8 +31,8 @@
 #      See the License for the specific language governing permissions and
 #      limitations under the License.
 
-from collections import Mapping, MutableMapping, OrderedDict
-
+from collections.abc import Mapping, MutableMapping
+from collections import OrderedDict
 
 class CaseInsensitiveDict(MutableMapping):
     """A case-insensitive ``dict``-like object.