diff --git a/python/parallel_advect.py b/python/parallel_advect.py
index a1229d8b..74b01084 100644
--- a/python/parallel_advect.py
+++ b/python/parallel_advect.py
@@ -214,7 +214,7 @@ class ReactionModel(object):
 class PhreeqcCalculator(object):
     """All PHREEQC calculations happen here.
 
-    This is the only place where we interact wit IPhreeqc.
+    This is the only place where we interact with IPhreeqc.
     Each instance of this class might run in a different
     process using `multiprocessing`.
     """