diff --git a/.github/workflows/tests-ubuntu.yml b/.github/workflows/tests-ubuntu.yml
index 75a06bd..013ca97 100644
--- a/.github/workflows/tests-ubuntu.yml
+++ b/.github/workflows/tests-ubuntu.yml
@@ -7,11 +7,17 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "pypy3.10"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "pypy3.10", "pypy3.11"]
 
     steps:
     - uses: actions/checkout@v4
 
+    - name: Install system libraries
+      if: contains(matrix.python-version, 'pypy')
+      run: |
+        sudo apt-get update
+        sudo apt-get install libxml2-dev libxslt-dev
+
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v5
       with: