diff --git a/wrangle.Rmd b/wrangle.Rmd
index 732fb73..2327a5f 100644
--- a/wrangle.Rmd
+++ b/wrangle.Rmd
@@ -38,7 +38,7 @@ frame_data(
 )
 ```
 
-## Tibbles vs data frames
+## Tibbles vs. data frames
 
 There are two main differences in the usage of a data frame vs a tibble: printing, and subsetting.