diff --git a/data-transform.qmd b/data-transform.qmd
index a0c6b28..5113ec4 100644
--- a/data-transform.qmd
+++ b/data-transform.qmd
@@ -294,7 +294,7 @@ A particularly useful argument is `"used"` which allows you to see the inputs an
 
 ```{r}
 flights |> 
-  mutate(,
+  mutate(
     gain = dep_delay - arr_delay,
     hours = air_time / 60,
     gain_per_hour = gain / hours,