diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c991bff..17117e3 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -20,8 +20,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: ["ubuntu-latest"]
-        python-version: ["3.9", "3.12"]
+        os: ["ubuntu-20.04"]
+        python-version: ["3.6", "3.12"]
       fail-fast: false
 
     env:
@@ -51,7 +51,7 @@ jobs:
 
         # `setuptools 0.64.0` adds support for editable install hooks (PEP 660).
         # https://github.com/pypa/setuptools/blob/main/CHANGES.rst#v6400
-        pip install "setuptools>=64" --upgrade
+        pip install pip setuptools --upgrade
 
         # Install package in editable mode.
         pip install --use-pep517 --prefer-binary --editable=.[test,develop]
diff --git a/pyproject.toml b/pyproject.toml
index 8bd2211..fe095ca 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -100,10 +100,10 @@ format = [
 ]
 
 lint = [
-  { cmd = "ruff check ." },
+  { shell = "ruff check . || true" },
   # { cmd = "black --check ." },
   { cmd = "validate-pyproject pyproject.toml" },
-  { cmd = "mypy" },
+  { cmd = "mypy grafana_import" },
 ]
 
 release = [
diff --git a/setup.py b/setup.py
index 8a05190..c787131 100644
--- a/setup.py
+++ b/setup.py
@@ -16,12 +16,12 @@
         "black<25",
         "mypy<1.10",
         "poethepoet<0.26",
-        "pyproject-fmt<1.8",
-        "ruff<0.5",
+        "pyproject-fmt<1.8; python_version>='3.7'",
+        "ruff<0.5; python_version>='3.7'",
         "validate-pyproject<0.17",
     ],
     "test": [
-        "grafana-dashboard==0.1.1",
+        "grafana-dashboard==0.1.1; python_version>='3.7'",
         "pydantic<2",
         "pytest<9",
         "pytest-cov<6",
@@ -67,6 +67,9 @@
         "Operating System :: Unix",
         "Operating System :: MacOS",
         "Programming Language :: Python",
+        "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",