diff --git a/asyncer/_compat.py b/asyncer/_compat.py
index ade175e8..805b5036 100644
--- a/asyncer/_compat.py
+++ b/asyncer/_compat.py
@@ -1,6 +1,4 @@
-# AnyIO 4.1.0 renamed cancellable to abandon_on_cancel
-import importlib
-import importlib.metadata
+import inspect
 from typing import Callable, TypeVar, Union
 
 import anyio
@@ -8,30 +6,27 @@
 from anyio import CapacityLimiter
 from typing_extensions import TypeVarTuple, Unpack
 
-ANYIO_VERSION = importlib.metadata.version("anyio")
-
 T_Retval = TypeVar("T_Retval")
 PosArgsT = TypeVarTuple("PosArgsT")
 
-if ANYIO_VERSION >= "4.1.0":
+# Use abandon_on_cancel if available
+RUN_SYNC_AOC = (
+    "abandon_on_cancel" in inspect.getfullargspec(anyio.to_thread.run_sync).kwonlyargs
+)
+
 
-    async def run_sync(
-        func: Callable[[Unpack[PosArgsT]], T_Retval],
-        *args: Unpack[PosArgsT],
-        abandon_on_cancel: bool = False,
-        limiter: Union[CapacityLimiter, None] = None,
-    ) -> T_Retval:
+async def run_sync(
+    func: Callable[[Unpack[PosArgsT]], T_Retval],
+    *args: Unpack[PosArgsT],
+    abandon_on_cancel: bool = False,
+    limiter: Union[CapacityLimiter, None] = None,
+) -> T_Retval:
+    # AnyIO 4.1.0 renamed cancellable to abandon_on_cancel
+    if RUN_SYNC_AOC:
         return await anyio.to_thread.run_sync(
             func, *args, abandon_on_cancel=abandon_on_cancel, limiter=limiter
         )
-else:
-
-    async def run_sync(
-        func: Callable[[Unpack[PosArgsT]], T_Retval],
-        *args: Unpack[PosArgsT],
-        abandon_on_cancel: bool = False,
-        limiter: Union[CapacityLimiter, None] = None,
-    ) -> T_Retval:
+    else:
         return await anyio.to_thread.run_sync(
             func, *args, cancellable=abandon_on_cancel, limiter=limiter
         )