diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5d6a9a39080575c13629e40af6c5373e3a8901c0..1fa93435d6ccea8f188732c2d9cfcfbd8ca55f83 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -44,7 +44,7 @@ before_script:
   before_script:
     - mkdir -p $R_LIBS_USER
     - echo "R_LIBS='$R_LIBS_USER'" > .Renviron
-    - apt-get update && apt-get install -y tk
+    - apt-get update && apt-get install -y tk libstdc++-11-dev
     - R -q -e 'remotes::update_packages("sm")'
     - R -q -e 'install.packages("vioplot")'
     - R -q -e 'remotes::install_deps(dependencies = TRUE)'