diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index fb66263..f01995d 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -10,7 +10,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: deps
-      run: sudo apt-get install mlton smlnj libsmlnj-smlnj polyml libpolyml-dev
+      run: sudo apt-get install mlton smlnj libsmlnj-smlnj polyml libpolyml-dev git mercurial subversion
     - name: prepare
       run: |
         git config --global user.email "nobody@example.com"