diff --git a/relational-data.Rmd b/relational-data.Rmd
index 283bea2..23d40df 100644
--- a/relational-data.Rmd
+++ b/relational-data.Rmd
@@ -140,7 +140,7 @@ There are three ways that the keys might match: one-to-one, one-to-many, and man
     inner_join(x, y, by = "key")
     ```
     
-*   In a one-to-many match, each key in `x` matches multiple keys in `y`. This
+*   In a one-to-many match, each key in `y` matches multiple keys in `x`. This
     is useful when you want to add in additional information.
     
     ```{r, echo = FALSE, out.width = "100%"}