diff --git a/zipline/algorithm.py b/zipline/algorithm.py
index 69f80ec5..f409062d 100644
--- a/zipline/algorithm.py
+++ b/zipline/algorithm.py
@@ -1465,8 +1465,8 @@ class TradingAlgorithm(object):
 
         Parameters
         ----------
-        commision : PerShare, PerTrade, or PerDollar
-            The commision model to use.
+        commission : PerShare, PerTrade, or PerDollar
+            The commission model to use.
 
         See Also
         --------
diff --git a/zipline/api.pyi b/zipline/api.pyi
index bb7faac5..3a1f6ba7 100644
--- a/zipline/api.pyi
+++ b/zipline/api.pyi
@@ -508,8 +508,8 @@ def set_commission(commission):
 
     Parameters
     ----------
-    commision : PerShare, PerTrade, or PerDollar
-        The commision model to use.
+    commission : PerShare, PerTrade, or PerDollar
+        The commission model to use.
 
     See Also
     --------