diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9bbe32b..55984e8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -123,6 +123,31 @@ jobs:
           name: cibw-sdist
           path: dist/*.tar.gz
 
+  # Regression test borrowed from https://github.com/mmore500/hstrat/blob/ba7b19d0f0561303b6bf789d5024a323aa5993fc/.github/workflows/ci.yaml#L201
+  packaging-sdist:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: "recursive"        
+      - name: Build sdist
+        run: |
+          python3 -m venv env
+          source env/bin/activate
+          python3 -m pip install -r requirements.txt
+          python3 setup.py sdist
+          tree dist
+          deactivate
+      - name: Upgrade pip
+        run: python3 -m pip install pip --upgrade
+      - name: Install from sdist
+        run: python3 -m pip install dist/*.tar.gz
+      - name: Test install
+        run: |
+          find . -type f -name '*.py' -exec rm {} \;
+          python3 -c "import phylotrackpy; print(phylotrackpy.__version__)"
+
   upload_pypi:
     needs: [build_wheels, build_sdist, test]
     runs-on: ubuntu-latest
diff --git a/MANIFEST.in b/MANIFEST.in
new file mode 100644
index 0000000..e1e1bf4
--- /dev/null
+++ b/MANIFEST.in
@@ -0,0 +1,2 @@
+include systematics_bindings.cpp
+recursive-include Empirical *.hpp
\ No newline at end of file
diff --git a/setup.py b/setup.py
index 37edc5f..c47aab8 100644
--- a/setup.py
+++ b/setup.py
@@ -39,5 +39,5 @@
     cmdclass={"build_ext": build_ext},
     zip_safe=False,
     python_requires=">=3.7",
-    packages=['phylotrackpy'],
+    packages=['phylotrackpy']
 )