diff --git a/astrodendro/dendrogram.py b/astrodendro/dendrogram.py
index 42750f7..72cfeeb 100644
--- a/astrodendro/dendrogram.py
+++ b/astrodendro/dendrogram.py
@@ -5,7 +5,12 @@
 # - An ancestor is the largest structure that a structure is part of
 
 import numpy as np
-from collections import Iterable
+try:
+    # Python <= 3.9
+    from collections import Iterable
+except ImportError:
+    # Python > 3.9
+    from collections.abc import Iterable
 import copy
 import warnings