diff --git a/requirements.txt b/requirements.txt
index 85bac42914..4f302d5c70 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ requests<=2.31.0
 docker>=6.1.0, <8
 urllib3>=1.26.0,<3
 python-dateutil
-psutil >= 3.0.1, < 7
+psutil >= 6.1.0, < 7
 PyPubSub >=4.0.3, <5
 addict>=2.2.1, <2.5
 backports.zoneinfo[tzdata];python_version<"3.9"
diff --git a/src/toil/lib/threading.py b/src/toil/lib/threading.py
index 27a74d7a17..997a3d8c14 100644
--- a/src/toil/lib/threading.py
+++ b/src/toil/lib/threading.py
@@ -252,7 +252,7 @@ def cpu_count() -> int:
         return cast(int, cached)
 
     # Get the fallback answer of all the CPUs on the machine
-    psutil_cpu_count = cast(Optional[int], psutil.cpu_count(logical=True))
+    psutil_cpu_count: int | None = psutil.cpu_count(logical=True)
     if psutil_cpu_count is None:
         logger.debug("Could not retrieve the logical CPU count.")