diff --git a/pre_commit/commands/hook_impl.py b/pre_commit/commands/hook_impl.py
index 85517ece..d792cd98 100644
--- a/pre_commit/commands/hook_impl.py
+++ b/pre_commit/commands/hook_impl.py
@@ -111,12 +111,10 @@ def _ns(
 
 
 def _rev_exists(rev: str) -> bool:
-    return not (
-        not subprocess.call(
-            ('git', 'cat-file', '-e', rev),
-            stderr=subprocess.DEVNULL,
-        )
-    )
+    return not bool(subprocess.call(
+        ('git', 'cat-file', '-e', rev),
+        stderr=subprocess.DEVNULL,
+    ))
 
 
 def _pre_push_ns(