diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e5001df..c02fb0a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -44,6 +44,8 @@ jobs:
       fail-fast: false
     steps:
       - uses: actions/checkout@v4
+      - name: Install primecount C library
+        run: sudo apt-get install primecount
       - uses: haskell-actions/setup@v2
         with:
           ghc-version: ${{ matrix.ghc }}