diff --git a/python/py-fuzzer/fuzz.py b/python/py-fuzzer/fuzz.py
index 090f329b32..a9659b8cf0 100644
--- a/python/py-fuzzer/fuzz.py
+++ b/python/py-fuzzer/fuzz.py
@@ -33,7 +33,7 @@ from collections.abc import Callable
 from dataclasses import KW_ONLY, dataclass
 from functools import partial
 from pathlib import Path
-from typing import NewType, NoReturn, assert_never
+from typing import Final, NewType, NoReturn, assert_never
 
 from pysource_codegen import generate as generate_random_code
 from pysource_minimize import CouldNotMinimize, minimize as minimize_repro
@@ -44,6 +44,12 @@ MinimizedSourceCode = NewType("MinimizedSourceCode", str)
 Seed = NewType("Seed", int)
 ExitCode = NewType("ExitCode", int)
 
+TY_TARGET_PLATFORM: Final = "linux"
+
+# ty supports `--python-version=3.8`, but typeshed only supports 3.9+,
+# so that's probably the oldest version we can usefully test with.
+OLDEST_SUPPORTED_PYTHON: Final = "3.9"
+
 
 def ty_contains_bug(code: str, *, ty_executable: Path) -> bool:
     """Return `True` if the code triggers a panic in type-checking code."""
@@ -51,7 +57,17 @@ def ty_contains_bug(code: str, *, ty_executable: Path) -> bool:
         input_file = Path(tempdir, "input.py")
         input_file.write_text(code)
         completed_process = subprocess.run(
-            [ty_executable, "check", input_file], capture_output=True, text=True
+            [
+                ty_executable,
+                "check",
+                input_file,
+                "--python-version",
+                OLDEST_SUPPORTED_PYTHON,
+                "--python-platform",
+                TY_TARGET_PLATFORM,
+            ],
+            capture_output=True,
+            text=True,
         )
     return completed_process.returncode not in {0, 1, 2}
 
@@ -137,7 +153,10 @@ class FuzzResult:
                 case Executable.RUFF:
                     panic_message = f"The following code triggers a {new}parser bug:"
                 case Executable.TY:
-                    panic_message = f"The following code triggers a {new}ty panic:"
+                    panic_message = (
+                        f"The following code triggers a {new}ty panic with "
+                        f"`--python-version={OLDEST_SUPPORTED_PYTHON} --python-platform={TY_TARGET_PLATFORM}`:"
+                    )
                 case _ as unreachable:
                     assert_never(unreachable)
 
diff --git a/python/py-fuzzer/pyproject.toml b/python/py-fuzzer/pyproject.toml
index 52bc17f25a..de1af7cc26 100644
--- a/python/py-fuzzer/pyproject.toml
+++ b/python/py-fuzzer/pyproject.toml
@@ -19,7 +19,7 @@ requires = ["hatchling"]
 build-backend = "hatchling.build"
 
 [dependency-groups]
-dev = ["mypy", "ruff"]
+dev = ["mypy", "ruff", "ty"]
 
 [tool.hatch.build.targets.wheel]
 include = ["fuzz.py"]
diff --git a/python/py-fuzzer/uv.lock b/python/py-fuzzer/uv.lock
index 7716e16da9..096049a945 100644
--- a/python/py-fuzzer/uv.lock
+++ b/python/py-fuzzer/uv.lock
@@ -89,6 +89,7 @@ dependencies = [
 dev = [
     { name = "mypy" },
     { name = "ruff" },
+    { name = "ty" },
 ]
 
 [package.metadata]
@@ -104,6 +105,7 @@ requires-dist = [
 dev = [
     { name = "mypy" },
     { name = "ruff" },
+    { name = "ty" },
 ]
 
 [[package]]
@@ -196,6 +198,31 @@ wheels = [
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 ]
 
+[[package]]
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+version = "0.0.1a32"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/26/92/8da015685fb83734a2a83de02080e64d182509de77fa9bcf3eed12eeab4b/ty-0.0.1a32.tar.gz", hash = "sha256:12f62e8a3dd0eaeb9557d74b1c32f0616ae40eae10a4f411e1e2a73225f67ff2", size = 4689151, upload-time = "2025-12-05T21:04:26.885Z" }
+wheels = [
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+    { url = "https://files.pythonhosted.org/packages/19/20/eaff31048e2f309f37478f7d715c8de9f9bab03cba4758da27b9311147af/ty-0.0.1a32-py3-none-macosx_10_12_x86_64.whl", hash = "sha256:07f1dce88ad6028fb14665aefe4e6697012c34bd48edd37d02b7eb6a833dbf62", size = 9434094, upload-time = "2025-12-05T21:04:03.383Z" },
+    { url = "https://files.pythonhosted.org/packages/67/d4/ea8ed57d11b81c459f23561fd6bfb0f54a8d4120cf72541e3bdf71d46202/ty-0.0.1a32-py3-none-macosx_11_0_arm64.whl", hash = "sha256:8fab7ed12528c77ddd600a9638ca859156a53c20f1e381353fa87a255bd397eb", size = 8980296, upload-time = "2025-12-05T21:04:28.912Z" },
+    { url = "https://files.pythonhosted.org/packages/49/02/3ce98bbfbb3916678d717ee69358d38a404ca9a39391dda8874b66dd5ee7/ty-0.0.1a32-py3-none-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:ace395280fc21e25eff0a53cfbd68170f90a4b8ef2f85dfabe1ecbca2ced456b", size = 9263054, upload-time = "2025-12-05T21:04:05.619Z" },
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+
 [[package]]
 name = "typing-extensions"
 version = "4.15.0"