diff --git a/wntr/utils/ordered_set.py b/wntr/utils/ordered_set.py
index 80079438d..53a9c341a 100644
--- a/wntr/utils/ordered_set.py
+++ b/wntr/utils/ordered_set.py
@@ -15,7 +15,7 @@ def __init__(self, iterable=None):
         Parameters
         ----------
         iterable: Iterable
-            An iterable with wich to initialize the set.
+            An iterable with which to initialize the set.
         """
         self._data = OrderedDict()
         if iterable is not None: