diff --git a/modern_3_indexes.ipynb b/modern_3_indexes.ipynb
index ad33cbd..0436b18 100644
--- a/modern_3_indexes.ipynb
+++ b/modern_3_indexes.ipynb
@@ -1576,7 +1576,7 @@
    "metadata": {},
    "source": [
     "This lets you focus on doing the operation, rather than manually aligning things, ensuring that the arrays are the same length and in the same order.\n",
-    "By deault, missing values are inserted where the two don't align.\n",
+    "By default, missing values are inserted where the two don't align.\n",
     "You can use the method version of any binary operation to specify a `fill_value`"
    ]
   },