diff --git a/.github/workflows/lint-test-docs.yml b/.github/workflows/lint-test-docs.yml
index 47bedd5..1254062 100644
--- a/.github/workflows/lint-test-docs.yml
+++ b/.github/workflows/lint-test-docs.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "pypy3.8", "pypy3.9"]
+        python-version: ["3.7", "3.8", "3.9", "3.10", "3.11","pypy3.7", "pypy3.8", "pypy3.9"]
 
     steps:
       - uses: actions/checkout@v3
@@ -27,4 +27,4 @@ jobs:
           python -m pytest
       - name: Build docs
         run: |
-          python -m sphinx-build -b html docs docs/_build/html
+          python -m sphinx.cmd.build -b html docs docs/_build/html
diff --git a/pyproject.toml b/pyproject.toml
index 7704bf5..1038cbf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -10,7 +10,7 @@ authors = [
     {name = "Bruno M. Custódio"},
 ]
 readme = "README.rst"
-requires-python = ">=3.8"
+requires-python = ">=3.7"
 
 dependencies = [
 ]
@@ -22,8 +22,8 @@ repository = "https://github.com/frederickjansen/polyline"
 [project.optional-dependencies]
 dev = [
     "pytest~=7.0",
-    "pytest-cov~=4.0.0",
-    "pylint~=2.14.0",
+    "pytest-cov~=4.0",
+    "pylint~=2.15.10",
     "sphinx~=4.2.0",
     "sphinx-rtd-theme~=1.0.0",
     "toml~=0.10.2",
diff --git a/src/polyline/polyline.py b/src/polyline/polyline.py
index 8143870..10fbd76 100644
--- a/src/polyline/polyline.py
+++ b/src/polyline/polyline.py
@@ -4,6 +4,7 @@
 import io
 import itertools
 import math
+from typing import List
 
 
 def _pcitr(iterable):
@@ -43,7 +44,7 @@ def _trans(value, index):
     return ~(result >> 1) if comp else (result >> 1), index
 
 
-def decode(expression: str, precision: int = 5, geojson: bool = False) -> list[tuple[float, float]]:
+def decode(expression: str, precision: int = 5, geojson: bool = False) -> List[tuple[float, float]]:
     """
     Decode a polyline string into a set of coordinates.
 
@@ -68,7 +69,7 @@ def decode(expression: str, precision: int = 5, geojson: bool = False) -> list[t
     return coordinates
 
 
-def encode(coordinates: list[tuple[float, float]], precision: int = 5, geojson: bool = False) -> str:
+def encode(coordinates: List[tuple[float, float]], precision: int = 5, geojson: bool = False) -> str:
     """
     Encode a set of coordinates in a polyline string.