diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 133d4887..769fa670 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -26,7 +26,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["macos-latest", "ubuntu-latest", "windows-latest"]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.11", "3.12"]
         parallel: ["", "--test-parallel"]
         storage-layout: ["solidity", "generic"]
 
diff --git a/pyproject.toml b/pyproject.toml
index df346d68..16287655 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,7 @@ classifiers = [
     "License :: OSI Approved :: GNU Affero General Public License v3",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.9"
+requires-python = ">=3.11"
 dependencies = [
     "sortedcontainers>=2.4.0",
     "toml>=0.10.2",
@@ -35,7 +35,7 @@ halmos = "halmos.__main__:main"
 "Homepage" = "https://github.com/a16z/halmos"
 
 [tool.black]
-target-version = ["py39", "py310", "py311", "py312"]
+target-version = ["py311", "py312"]
 
 [tool.pytest.ini_options]
 # TODO: re-add test_traces.py when we have a better way to support it in CI