diff --git a/pre_commit/commands/hook_impl.py b/pre_commit/commands/hook_impl.py
index dc9666f5..815b22b2 100644
--- a/pre_commit/commands/hook_impl.py
+++ b/pre_commit/commands/hook_impl.py
@@ -111,11 +111,9 @@ def _ns(
 
 
 def _rev_exists(rev: str) -> bool:
-    return not bool(
-        subprocess.call(
-            ('git', 'cat-file', '-e', rev),
-            stderr=subprocess.DEVNULL,
-        ),
+    return not subprocess.call(
+        ('git', 'cat-file', '-e', rev),
+        stderr=subprocess.DEVNULL,
     )