diff --git a/ci/lint/04_install.sh b/ci/lint/04_install.sh
index 80d0df4a7..fae424051 100755
--- a/ci/lint/04_install.sh
+++ b/ci/lint/04_install.sh
@@ -6,6 +6,10 @@
 
 export LC_ALL=C
 
+travis_retry sudo apt update && sudo apt install -y clang-format-9
+sudo update-alternatives --install /usr/bin/clang-format      clang-format      $(which clang-format-9     ) 100
+sudo update-alternatives --install /usr/bin/clang-format-diff clang-format-diff $(which clang-format-diff-9) 100
+
 travis_retry pip3 install codespell==1.17.1
 travis_retry pip3 install flake8==3.8.3
 travis_retry pip3 install yq