diff --git a/sdks/python/pyproject.toml b/sdks/python/pyproject.toml
index 67175d77f..9162b6631 100644
--- a/sdks/python/pyproject.toml
+++ b/sdks/python/pyproject.toml
@@ -52,7 +52,14 @@ Repository = "https://github.com/tokencanopy/e2a"
 Documentation = "https://e2a.dev"
 
 [project.optional-dependencies]
-dev = ["pytest>=7", "pytest-cov>=5", "pytest-httpx", "anyio[trio]", "pyyaml>=6", "build", "twine", "mypy>=1.10,<1.19"]
+# pydantic<2.14 here is for the mypy gate, not a runtime constraint: [tool.mypy]
+# checks under python_version 3.9 and follows imports into the installed
+# pydantic, while CI installs on 3.12. pydantic 2.14 requires Python >=3.10 and
+# uses `match` statements, which that 3.9 grammar rejects ("Pattern matching is
+# only supported in Python 3.10 and greater"). A real 3.9 user resolves 2.13.x,
+# so the dev install stays at what they get. Drop the cap when requires-python
+# moves to >=3.10.
+dev = ["pytest>=7", "pytest-cov>=5", "pytest-httpx", "anyio[trio]", "pyyaml>=6", "build", "twine", "mypy>=1.10,<1.19", "pydantic<2.14"]
 ws = ["websockets>=14"]
 
 # Unit-test coverage gate (pytest-cov). The OpenAPI-Generator client base under