diff --git a/session_1/session_1.Rmd b/session_1/session_1.Rmd
index d7ed953d61cc950bedd0adc765176410cdd0f0ce..3a1db58e4b9b6e2f731360bc0d5f7bd1684c9bc0 100644
--- a/session_1/session_1.Rmd
+++ b/session_1/session_1.Rmd
@@ -1013,7 +1013,7 @@ sessionInfo()
 ## Help on packages (when existing)
 
 ```R
-browseVignettes(ggplot2)
+browseVignettes("ggplot2")
 ```
 
 ## See you in [Session 2 : "Introduction to Tidyverse"](https://can.gitbiopages.ens-lyon.fr/R_basis/session_2.html)