diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7b5b796..c765953 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -38,6 +38,12 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
+      - name: Set up Python 3.7 to bootstrap py3.6
+        if: ${{ matrix.python-version == '3.6' }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.7
+
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4
         with:
@@ -47,7 +53,18 @@ jobs:
         run: |
           python -m pip install -U -r tests/requirements.txt
 
+      # Python 3.6 cannot install directly from a pyproject.toml
+      # Instead, build a wheel from py3.7 and then install it
+      - name: Install via wheel
+        if: ${{ matrix.python-version == '3.6' }}
+        run: |
+          python3.7 -m pip install build
+          python3.7 -m build
+          python --version
+          python -m pip install ./dist/*.whl
+
       - name: Install
+        if: ${{ matrix.python-version != '3.6' }}
         run: |
           python -m pip install .
 
@@ -115,14 +132,14 @@ jobs:
 
       - name: Install dependencies
         run: |
-          python -m pip install -U mypy
+          python -m pip install -U mypy peakrdl
 
       - name: Type Check
         run: |
           mypy --config-file tests/mypy.ini src/peakrdl_cheader
 
 #-------------------------------------------------------------------------------
-  build_sdist:
+  build:
     needs:
       - test
       - lint
@@ -137,17 +154,23 @@ jobs:
         with:
           python-version: "3.10"
 
+      - name: Install dependencies
+        run: |
+          python -m pip install -U build
+
       - name: Build sdist
-        run: python setup.py sdist
+        run: python -m build
 
       - uses: actions/upload-artifact@v3
         with:
-          path: dist/*.tar.gz
+          path: |
+            dist/*.tar.gz
+            dist/*.whl
 
 #-------------------------------------------------------------------------------
   deploy:
     needs:
-      - build_sdist
+      - build
 
     runs-on: ubuntu-latest
 
diff --git a/pyproject.toml b/pyproject.toml
index 0686899..5abde2d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,7 +5,7 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "peakrdl-cheader"
 dynamic = ["version"]
-requires-python = ">=3.7"
+requires-python = ">=3.6"
 dependencies = [
     "systemrdl-compiler >= 1.21.0, < 2",
     "jinja2",
@@ -23,11 +23,13 @@ classifiers = [
     "Development Status :: 4 - Beta",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3 :: Only",
     "Intended Audience :: Developers",
     "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
diff --git a/src/peakrdl_cheader/c_standards.py b/src/peakrdl_cheader/c_standards.py
index eebc276..d32b4cc 100644
--- a/src/peakrdl_cheader/c_standards.py
+++ b/src/peakrdl_cheader/c_standards.py
@@ -1,37 +1,49 @@
-from typing import Dict
+from typing import Dict, Tuple
 import enum
 
 class CStandard(enum.Enum):
 
-    def __init__(self, version: int, d: Dict[str, bool]) -> None:
+    def __init__(self, name: str, d: Dict[str, bool]) -> None:
         self.anon_unions = d.get("anon_unions", False)
         self.static_assert = d.get("static_assert", False)
         self.static_assert_needs_assert_h = d.get("static_assert_needs_assert_h", False)
 
         # Prevent Enum from flattening members into aliases
-        self._value_ = version
+        self._value_ = name
 
-    gnu23 = 23, {
+    gnu23 = "gnu23", {
         "anon_unions": True,
         "static_assert": True,
     }
 
-    gnu17 = 17, {
+    gnu17 = "gnu17", {
         "anon_unions": True,
         "static_assert": True,
         "static_assert_needs_assert_h": True,
     }
 
-    gnu11 = 11, {
+    gnu11 = "gnu11", {
         "anon_unions": True,
         "static_assert": True,
         "static_assert_needs_assert_h": True,
     }
 
-    gnu99 = 99, {}
+    gnu99 = "gnu99", {
+        "anon_unions": False,
+        "static_assert": False,
+        "static_assert_needs_assert_h": False,
+    }
 
-    gnu90 = 90, {}
+    gnu90 = "gnu90", {
+        "anon_unions": False,
+        "static_assert": False,
+        "static_assert_needs_assert_h": False,
+    }
 
-    gnu89 = 89, {}
+    gnu89 = "gnu89", {
+        "anon_unions": False,
+        "static_assert": False,
+        "static_assert_needs_assert_h": False,
+    }
 
     latest = gnu17 # gnu23 is still unreleased
diff --git a/src/peakrdl_cheader/header_generator.py b/src/peakrdl_cheader/header_generator.py
index b785913..6303397 100644
--- a/src/peakrdl_cheader/header_generator.py
+++ b/src/peakrdl_cheader/header_generator.py
@@ -21,7 +21,7 @@ def __init__(self, ds: DesignState) -> None:
         self.root_node = None
 
         self.f: TextIO
-        self.f = None
+        self.f = None # type: ignore
 
     def run(self, path: str, top_nodes: List[AddrmapNode]) -> None:
         with open(path, "w", encoding='utf-8') as f:
diff --git a/src/peakrdl_cheader/py.typed b/src/peakrdl_cheader/py.typed
new file mode 100644
index 0000000..e69de29
diff --git a/src/peakrdl_cheader/testcase_generator.py b/src/peakrdl_cheader/testcase_generator.py
index 11ad96e..1515101 100644
--- a/src/peakrdl_cheader/testcase_generator.py
+++ b/src/peakrdl_cheader/testcase_generator.py
@@ -45,10 +45,10 @@ def __init__(self, ds: DesignState) -> None:
         self.root_node = None
 
         self.root_struct_name: str
-        self.root_struct_name = None
+        self.root_struct_name = ""
 
         self.f: TextIO
-        self.f = None
+        self.f = None # type: ignore
 
         self.overlap_pair_stack: List[List[str]]
         self.overlap_pair_stack = []
@@ -150,7 +150,7 @@ def __init__(self, ds: DesignState) -> None:
         self.root_node = None
 
         self.f: TextIO
-        self.f = None
+        self.f = None # type: ignore
 
     def run(self, f: TextIO, top_nodes: List[AddrmapNode]) -> None:
         self.f = f
diff --git a/tests/.mypy.ini b/tests/.mypy.ini
deleted file mode 100644
index f785436..0000000
--- a/tests/.mypy.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[mypy]
-namespace_packages = True
-explicit_package_bases = True
diff --git a/tests/base.py b/tests/base.py
index 1ec665c..d651783 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -79,22 +79,20 @@ def do_export(self):
     def do_compile(self):
         args = [
             "gcc",
-            "--std", self.std.name,
+            "--std", self.std.value,
             os.path.join(self.output_dir, "out.h.test.c"),
             "-o", os.path.join(self.output_dir, "test.exe"),
         ]
-        ret = subprocess.run(args, capture_output=True)
+        ret = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
         print(" ".join(args))
         print(ret.stdout.decode('utf-8'))
-        print(ret.stderr.decode('utf-8'))
         self.assertEqual(ret.returncode, 0)
 
     def do_run(self):
         args = [os.path.join(self.output_dir, "test.exe")]
-        ret = subprocess.run(args, capture_output=True)
+        ret = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
         print(" ".join(args))
         print(ret.stdout.decode('utf-8'))
-        print(ret.stderr.decode('utf-8'))
         self.assertEqual(ret.returncode, 0)
 
     def do_test(self):
diff --git a/tests/mypy.ini b/tests/mypy.ini
new file mode 100644
index 0000000..f061b14
--- /dev/null
+++ b/tests/mypy.ini
@@ -0,0 +1,11 @@
+[mypy]
+namespace_packages = True
+explicit_package_bases = True
+
+[mypy-systemrdl.*]
+# Ignore missing py.typed in release
+ignore_missing_imports = True
+
+[mypy-peakrdl.*]
+# Ignore missing py.typed in release
+ignore_missing_imports = True
diff --git a/tests/run.sh b/tests/run.sh
index 326ca96..c4d6315 100755
--- a/tests/run.sh
+++ b/tests/run.sh
@@ -10,6 +10,7 @@ source .venv/bin/activate
 
 # Install test dependencies
 pip install -U pip setuptools wheel
+pip install peakrdl
 pip install -r requirements.txt
 
 # Install dut
@@ -28,4 +29,4 @@ coverage html -i -d htmlcov
 pylint --rcfile pylint.rc ../src/peakrdl_cheader
 
 # Run static type checking
-#mypy ../src/peakrdl_cheader
+mypy ../src/peakrdl_cheader