diff --git a/lists.Rmd b/lists.Rmd
index 7a6d88d..aa27b62 100644
--- a/lists.Rmd
+++ b/lists.Rmd
@@ -309,7 +309,7 @@ This pattern of looping over a list and doing something to each element is so co
 * `map_chr()` returns a character vector.
 * `map_df()`  returns a data frame.
 * `walk()`    returns nothing. Walk is a little different to the others because 
-  it's called exclusively its side effects, so it's described in more detail 
+  it's called exclusively for its side effects, so it's described in more detail 
   later in [walk](#walk).
 
 Each functions takes a list as input, applies a function to each piece, and then returns a new vector that's the same length as the input. The type of the vector is determine by the specific map function. Usually you want to use the most specific avaiable; using `map()` only as a fallback when there is no specialised equivalent available.