diff --git a/docker/Dockerfile b/docker/Dockerfile
index 5e6875c6..7eb6d1a6 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -10,7 +10,8 @@ RUN apt-get update && apt-get install -y --no-install-recommends apt-utils dialo
 RUN apt-get install -y --no-install-recommends \
     libxt6 \
     libpoppler-cpp-dev \
-    vim
+    vim \
+    libglpk40
 
 # Remove old symlinks to old pandoc
 RUN unlink /usr/lib/rstudio-server/bin/pandoc/pandoc
@@ -55,6 +56,9 @@ RUN Rscript -e  "install.packages( \
 COPY git_token.txt .
 COPY github_package_list.tsv .
 
+# cow needs this dependency:
+RUN Rscript -e  "devtools::install_version('gitcreds', version = '0.1.1', repos = 'http://cran.us.r-project.org')"
+
 # Didactr needs this dependency:
 RUN Rscript -e  "devtools::install_version('lifecycle', version = '1.0.0', repos = 'http://cran.us.r-project.org')"
 
diff --git a/docker/github_package_list.tsv b/docker/github_package_list.tsv
index 56e4aba6..f4ea241c 100644
--- a/docker/github_package_list.tsv
+++ b/docker/github_package_list.tsv
@@ -6,4 +6,5 @@ jhudsl/didactr	cde4598c10f2b5e2e31b47fe94ca1b02db420e10
 jhudsl/leanbuild	HEAD
 tidyverse/rvest	4fe39fb5089512d77b6a9cc026e5c895258ff6ce
 R-lib/testthat	e99155af85261e065192feb946dcfa6679cffae4
-rstudio/bookdown	88bc4ead8562ea281838041c795b38fc4a6a7165
\ No newline at end of file
+rstudio/bookdown	88bc4ead8562ea281838041c795b38fc4a6a7165
+jhudsl/cow	HEAD
\ No newline at end of file