diff --git a/robust-code.Rmd b/robust-code.Rmd
index 29750f2..cedf547 100644
--- a/robust-code.Rmd
+++ b/robust-code.Rmd
@@ -42,7 +42,7 @@ You might notice that these issues revolve around data frames. That's unfortunat
 
 ```{r}
 df <- data.frame(xy = c("x", "y"))
-# Character vectors work hard to work with for a long time, so R
+# Character vectors were hard to work with for a long time, so R
 # helpfully converts to a factor for you:
 class(df$xy)