diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2b23c5db..5f263962 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -13,7 +13,7 @@ on:
 jobs:
   unit-tests:
     name: unit tests
-    runs-on: ubuntu-24.04
+    runs-on: ${{ matrix.os }}
     timeout-minutes: 1
     strategy:
       fail-fast: false
@@ -22,13 +22,13 @@ jobs:
         #run: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
     steps:
     - uses: actions/checkout@v4
-    - name: setup python
+    - name: install uv and dependencies
       run: |
         curl -LsSf https://astral.sh/uv/install.sh | sh
         uv venv
         # TODO: remove setuptools once https://github.com/cython/cython/issues/5751 is fixed
         uv pip install -e .[testing,docs] setuptools
-    - run: uv run scons -j$(nproc)
+    - run: uv run scons -j8
     - run: uv run pytest .
 
   static-analysis:
diff --git a/SConstruct b/SConstruct
index 932ff26e..1434ca38 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1,9 +1,12 @@
 import os
 import subprocess
 import sysconfig
+import platform
 import numpy as np
 
 arch = subprocess.check_output(["uname", "-m"], encoding='utf8').rstrip()
+if platform.system() == "Darwin":
+  arch = "Darwin"
 
 python_path = sysconfig.get_paths()['include']
 cpppath = [
@@ -73,4 +76,4 @@ envCython["LIBS"] = python_libs
 
 Export('envCython')
 
-SConscript(['opendbc/can/SConscript'])
+SConscript(['opendbc/can/SConscript'])
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 0ffe4521..43c700c7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ description = "CAN bus databases and tools"
 license = { file = "LICENSE" }
 authors = [{ name = "Vehicle Researcher", email = "user@comma.ai" }]
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.9,<3.13"  # pycapnp doesn't work with 3.13
 
 urls = { "homepage" = "https://github.com/commaai/opendbc" }
 
diff --git a/test.sh b/test.sh
index a574da2f..6b6265b1 100755
--- a/test.sh
+++ b/test.sh
@@ -5,11 +5,9 @@ DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null && pwd)"
 cd $DIR
 
 # ensure we're up to date
-uv venv --allow-existing
+uv sync --all-extras
 source .venv/bin/activate
 
-uv pip install -e .[testing,docs]
-
 uv run scons -j8
 
 uv run pre-commit run --all-files