diff --git a/lefthook.yml b/lefthook.yml
index ff45bb65..4b9f2fc9 100644
--- a/lefthook.yml
+++ b/lefthook.yml
@@ -17,6 +17,10 @@ post-commit:
       run: bash .githooks/post-commit
 
 pre-push:
+  # piped: true forces serial execution. Both sync-check and git-lfs
+  # read from stdin (git pipes the push refspec to pre-push hooks);
+  # default parallel execution deadlocks with two stdin readers.
+  piped: true
   commands:
     sync-check:
       run: bash .githooks/pre-push