diff --git a/rstudio/Dockerfile b/rstudio/Dockerfile
index e4a4aec..8f9825f 100644
--- a/rstudio/Dockerfile
+++ b/rstudio/Dockerfile
@@ -49,6 +49,7 @@ RUN apt-get update && apt-get install -y \
 	&& /usr/sbin/update-locale LANG=en_US.UTF-8 \
 	&& rm -rf /var/lib/apt/lists/*
 
+# https://www.rstudio.com/products/rstudio/download/#download
 ENV RSTUDIO_VERSION 1.1.453
 
 # Download the source