diff --git a/coworker/config.py b/coworker/config.py
index 336d4af8..a25a7c2a 100644
--- a/coworker/config.py
+++ b/coworker/config.py
@@ -9,7 +9,10 @@ workspace path. Other permission grants remain global-only.
 
 from __future__ import annotations
 
-import tomllib
+try:
+    import tomllib  # stdlib since 3.11
+except ModuleNotFoundError:  # 3.10, the floor requires-python declares
+    import tomli as tomllib  # type: ignore[no-redef]
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any, Optional
diff --git a/pyproject.toml b/pyproject.toml
index 687dad70..3c1f10f4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,6 +34,8 @@ dependencies = [
     # IANA tz database for zoneinfo. Windows ships no system tz db, so without this every
     # named schedule timezone (UTC, Asia/Kolkata, …) silently falls back to local time.
     "tzdata; sys_platform == 'win32'",
+    # tomllib landed in the 3.11 stdlib; on the 3.10 floor config.py falls back to tomli.
+    "tomli>=2; python_version < '3.11'",
 ]
 
 [project.optional-dependencies]