diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f0cf9d4..67f54c7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -19,10 +19,9 @@ jobs:
     strategy:
       matrix:
         python-version:
-          - 3.6
-          - 3.7
-          - 3.8
-          - 3.9
+          - "3.7"
+          - "3.8"
+          - "3.9"
           - "3.10"
           - "3.11"
           - "3.12"
@@ -30,20 +29,17 @@ jobs:
           - os: ubuntu-latest
 
           # older versions need older OS
-          - python-version: 3.6
-            os: ubuntu-20.04
+          - python-version: "3.7"
+            os: ubuntu-22.04
+
+          - python-version: "3.8"
+            os: ubuntu-22.04
 
     runs-on: ${{ matrix.os }}
 
     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:
@@ -53,18 +49,7 @@ 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 .
 
@@ -110,7 +95,7 @@ jobs:
 
       - name: Install dependencies
         run: |
-          python -m pip install -U pylint
+          python -m pip install -r tests/requirements.txt
 
       - name: Install
         run: |
@@ -132,7 +117,11 @@ jobs:
 
       - name: Install dependencies
         run: |
-          python -m pip install -U mypy peakrdl
+          python -m pip install -r tests/requirements.txt
+
+      - name: Install
+        run: |
+          python -m pip install .
 
       - name: Type Check
         run: |
@@ -161,8 +150,9 @@ jobs:
       - name: Build sdist
         run: python -m build
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
+          name: dist
           path: |
             dist/*.tar.gz
             dist/*.whl
@@ -180,9 +170,9 @@ jobs:
     # Only publish when a GitHub Release is created.
     if: github.event_name == 'release'
     steps:
-      - uses: actions/download-artifact@v3
+      - uses: actions/download-artifact@v4
         with:
-          name: artifact
+          name: dist
           path: dist
 
       - uses: pypa/gh-action-pypi-publish@release/v1
diff --git a/pyproject.toml b/pyproject.toml
index 8cbefe3..8b38176 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,9 +5,9 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "peakrdl-cheader"
 dynamic = ["version"]
-requires-python = ">=3.6"
+requires-python = ">=3.7"
 dependencies = [
-    "systemrdl-compiler >= 1.21.0, < 2",
+    "systemrdl-compiler >= 1.29.0, < 2",
     "jinja2",
 ]
 
@@ -26,13 +26,6 @@ classifiers = [
     "Development Status :: 5 - Production/Stable",
     "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)",
@@ -40,6 +33,11 @@ classifiers = [
     "Topic :: Scientific/Engineering :: Electronic Design Automation (EDA)",
 ]
 
+[project.optional-dependencies]
+cli = [
+    "peakrdl-cli >= 1.2.3",
+]
+
 [project.urls]
 Source = "https://github.com/SystemRDL/PeakRDL-cheader"
 Tracker = "https://github.com/SystemRDL/PeakRDL-cheader/issues"
diff --git a/src/peakrdl_cheader/design_state.py b/src/peakrdl_cheader/design_state.py
index 4a39e2f..506e8ad 100644
--- a/src/peakrdl_cheader/design_state.py
+++ b/src/peakrdl_cheader/design_state.py
@@ -21,11 +21,11 @@ def __init__(self, top_node: AddrmapNode, kwargs: Any) -> None:
         #------------------------
         # Each reg that has overlapping fields generates an entry:
         #   reg_path : list of field names involved in overlap
-        self.overlapping_fields = {} # type: Dict[str, List[str]]
+        self.overlapping_fields: Dict[str, List[str]] = {}
 
         # Pairs of overlapping registers
         #   first_reg_path : partner_register_name
-        self.overlapping_reg_pairs = {} # type: Dict[str, str]
+        self.overlapping_reg_pairs: Dict[str, str] = {}
 
         #------------------------
         # Extract compiler args