diff --git a/appendix b/appendix
index 37c629e..c0fe149 100644
--- a/appendix
+++ b/appendix
@@ -14,7 +14,8 @@ ENV R_HOME="/usr/local/lib/R"
 ENV TZ="Etc/UTC"
 
 COPY ${REPO_DIR}/install_R_source.sh /rocker_scripts/install_R_source.sh
-RUN cd / && /rocker_scripts/install_R_source.sh
+RUN cd / && \
+  /rocker_scripts/install_R_source.sh
 
 # Revert to default user
 USER ${NB_USER}