diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1169d839..f41cf42c 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -9,8 +9,7 @@ jobs:
     strategy:
       matrix:
         # Oldest non-EOL and newest released
-        # scipy-stubs does not support Python 3.9
-        python-version: ["3.10", "3.13"]
+        python-version: ["3.9", "3.13"]
         # Tier 1 OSes
         os: ["ubuntu-latest", "windows-latest", "macos-latest"]
       fail-fast: false
@@ -35,6 +34,12 @@ jobs:
       - name: Install dependencies
         run: python -m pip install --group tests
 
+      - name: Install scipy-stubs on Python 3.9
+        if: ${{ matrix.python-version == '3.9' }}
+        # scipy-stubs claims to not support Python 3.9
+        # Manually install last version claiming Python 3.10 support
+        run: python -m pip install 'scipy-stubs<1.16' 'optype<0.10' --ignore-requires-python
+
       - name: Run pyright tests
         uses: jakebailey/pyright-action@v2
         with:
diff --git a/pyproject.toml b/pyproject.toml
index 8bf3c26a..a2af65a4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,7 +19,9 @@ tests = [
     "matplotlib >=3.8",
     "pandas-stubs",
     "pytest",
-    "scipy-stubs",
+    # scipy-stubs claims to not support Python 3.9
+    # Manually install it separately (see .github/workflows/test.yml)
+    "scipy-stubs; python_version >= '3.10'",
     "types-networkx",
     "typing_extensions",
 
@@ -30,7 +32,12 @@ tests = [
     "sympy",
     "vispy",
 ]
-dev = [{ include-group = "hygiene" }, { include-group = "tests" }]
+dev = [
+    { include-group = "hygiene" },
+    { include-group = "tests" },
+    # Test scripts force a dependency update using pip, which doesn't come bundled in all venvs
+    "pip",
+]
 
 
 # Allow these stubs to be installed from GitHub
diff --git a/tests/run_tests.py b/tests/run_tests.py
index bd0e6529..8e6c5875 100644
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -8,6 +8,10 @@ def install_requirements() -> None:
     print("\nInstalling requirements...")
     subprocess.check_call((sys.executable, "-m", "pip", "install", "pip>=25.1"))
     subprocess.check_call((sys.executable, "-m", "pip", "install", "--upgrade", "--group", "tests"))
+    if sys.version_info < (3, 10):
+        subprocess.check_call(
+            (sys.executable, "-m", "pip", "install", "scipy-stubs<1.16", "optype<0.10", "--ignore-requires-python")
+        )
 
 
 def run_pyright() -> subprocess.CompletedProcess[bytes]: