diff --git a/pre_commit/commands/hook_impl.py b/pre_commit/commands/hook_impl.py
index c2af005c..85517ece 100644
--- a/pre_commit/commands/hook_impl.py
+++ b/pre_commit/commands/hook_impl.py
@@ -111,10 +111,12 @@ def _ns(
 
 
 def _rev_exists(rev: str) -> bool:
-    return not (not subprocess.call(
-        ('git', 'cat-file', '-e', rev),
-        stderr=subprocess.DEVNULL,
-    ))
+    return not (
+        not subprocess.call(
+            ('git', 'cat-file', '-e', rev),
+            stderr=subprocess.DEVNULL,
+        )
+    )
 
 
 def _pre_push_ns(