diff --git a/AGENTS.md b/AGENTS.md
index 1875873..d40a7e9 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -33,7 +33,7 @@
 
 ## Architecture
 
-- The project uses Python and must be Python 3.12 compatible.
+- The project uses Python and must be Python 3.12 and Python 3.10 compatible.
 - Library code lives in the `openvixdisklib` package (`nfc_auth`, `nfc_open`,
   `openvixdisklib`).
 - The `.vddk` dir contains the VDDK libraries and their dependencies, including
diff --git a/README.md b/README.md
index e744979..1345fdb 100644
--- a/README.md
+++ b/README.md
@@ -22,10 +22,12 @@ Not implemented: compression open flags other than FastLZ, CBT /
 allocated-block queries, disk geometry (`DDB_GET`), encrypted disks,
 and direct ESXi `ha-nfc` without vCenter `vpxa-nfc`.
 
+Requires Python 3.10 or later.
+
 ## Install
 
 ```bash
-python3.12 -m venv .venv
+python3 -m venv .venv
 .venv/bin/pip install -e .
 ```
 
diff --git a/openvixdisklib/nfc_auth.py b/openvixdisklib/nfc_auth.py
index e2b835e..75f4260 100644
--- a/openvixdisklib/nfc_auth.py
+++ b/openvixdisklib/nfc_auth.py
@@ -21,7 +21,6 @@ import contextlib
 import hashlib
 import socket
 import ssl
-from typing import Self
 
 from pyVim.connect import Disconnect, SmartConnect
 from pyVmomi import vim
@@ -395,7 +394,7 @@ class NfcAuthSession:
         finally:
             Disconnect(self.si)
 
-    def __enter__(self) -> Self:
+    def __enter__(self) -> NfcAuthSession:
         return self
 
     def __exit__(self, exc_type, exc, tb) -> None:
diff --git a/openvixdisklib/nfc_open.py b/openvixdisklib/nfc_open.py
index 8bccd73..05d21d4 100644
--- a/openvixdisklib/nfc_open.py
+++ b/openvixdisklib/nfc_open.py
@@ -25,7 +25,6 @@ import os
 import socket
 import ssl
 import struct
-from typing import Self
 
 from openvixdisklib import fastlz
 from openvixdisklib.nfc_auth import NfcAuthSession, _ssl_client_context
@@ -385,7 +384,7 @@ class NfcDisk:
             except OSError:
                 pass
 
-    def __enter__(self) -> Self:
+    def __enter__(self) -> NfcDisk:
         return self
 
     def __exit__(self, exc_type, exc, tb) -> None:
diff --git a/ruff.toml b/ruff.toml
index c64fc5c..a6459b1 100644
--- a/ruff.toml
+++ b/ruff.toml
@@ -1,5 +1,5 @@
 line-length = 88
-target-version = "py312"
+target-version = "py310"
 
 [lint]
 # UP031: Allow percent formatting for now.
@@ -8,4 +8,5 @@ target-version = "py312"
 # BLE001: we'll allow catching Exception for now.
 # RUF015: enforces next() to be used when getting the first item of a list,
 #         may be enabled at a later time.
-ignore = ["UP031", "PIE790", "RUF100", "BLE001", "RUF015"]
+# PYI034: typing.Self requires Python 3.11; return the class instead.
+ignore = ["UP031", "PIE790", "RUF100", "BLE001", "RUF015", "PYI034"]
diff --git a/setup.cfg b/setup.cfg
index 55a6a75..f7fea88 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -14,7 +14,10 @@ classifier =
     Operating System :: OS Independent
     Programming Language :: Python
     Programming Language :: Python :: 3
+    Programming Language :: Python :: 3.10
+    Programming Language :: Python :: 3.11
     Programming Language :: Python :: 3.12
+python-requires = >=3.10
 
 [files]
 packages =