diff --git a/docker/Dockerfile b/docker/Dockerfile
index 49d6c379..1c0c6e08 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -43,7 +43,7 @@ RUN apt-get -y --no-install-recommends install \
     python3-pip  python3-dev
 
 # Commonly used R packages
-RUN Rscript -e  "install.packages( \
+RUN Rscript -e  "options(warn = 2);install.packages( \
     c('bookdown', \
       'here', \
       'leanpubr', \
@@ -56,7 +56,8 @@ RUN Rscript -e  "install.packages( \
       'servr', \
       'spelling', \
       'styler', \
-      'reticulate'))"
+      'reticulate'), \
+      repos = 'https://cloud.r-project.org/')"
 
 # cow needs this dependency:
 RUN Rscript -e  "devtools::install_version('gitcreds', version = '0.1.1', repos = 'http://cran.us.r-project.org')"
diff --git a/resources/TEMPLATE_Dockerfile b/resources/TEMPLATE_Dockerfile
index 46fc78d0..01ce1836 100644
--- a/resources/TEMPLATE_Dockerfile
+++ b/resources/TEMPLATE_Dockerfile
@@ -7,8 +7,9 @@ LABEL maintainer="your_email.com"
 #    package_name
 
 # Install a package from CRAN
-# RUN Rscript -e  "install.packages( \
-#    c('package_name'))"
+# RUN Rscript -e  "options(warn = 2);install.packages( \
+#    c('package_name'), \
+#    repos = 'https://cloud.r-project.org/')"
 
 # Install a package from Bioconductor
 # RUN Rscript -e "options(warn = 2); BiocManager::install( \