diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d69c9bf..acd671f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,7 +18,7 @@ jobs:
         if: ${{ ! matrix.library }}
       - name: Install library
         run: |
-          sudo apt-get install -y "automake" "libtool" "libmd4c-dev"
+          sudo apt-get install -y "automake" "libtool" "libmd4c-dev" "libmd4c-html0-dev"
         if: ${{ matrix.library }}
       - name: Setup PHP
         uses: shivammathur/setup-php@v2