diff --git a/src/toil/lib/threading.py b/src/toil/lib/threading.py
index 27a74d7a17..e24c7a619a 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 = psutil.cpu_count(logical=True)
     if psutil_cpu_count is None:
         logger.debug("Could not retrieve the logical CPU count.")