diff --git a/pre_commit/commands/hook_impl.py b/pre_commit/commands/hook_impl.py
index 18e5e9f5..f315c04d 100644
--- a/pre_commit/commands/hook_impl.py
+++ b/pre_commit/commands/hook_impl.py
@@ -114,7 +114,8 @@ def _pre_push_ns(
     remote_url = args[1]
 
     for line in stdin.decode().splitlines():
-        local_branch, local_sha, remote_branch, remote_sha = line.split()
+        parts = line.rsplit(maxsplit=3)
+        local_branch, local_sha, remote_branch, remote_sha = parts
         if local_sha == Z40:
             continue
         elif remote_sha != Z40 and _rev_exists(remote_sha):
diff --git a/tests/commands/hook_impl_test.py b/tests/commands/hook_impl_test.py
index b0159f8e..3e20874e 100644
--- a/tests/commands/hook_impl_test.py
+++ b/tests/commands/hook_impl_test.py
@@ -242,6 +242,18 @@ def test_run_ns_pre_push_new_branch_existing_rev(push_example):
     assert ns is None
 
 
+def test_run_ns_pre_push_ref_with_whitespace(push_example):
+    src, src_head, clone, _ = push_example
+
+    with cwd(clone):
+        args = ('origin', src)
+        line = f'HEAD^{{/ }} {src_head} refs/heads/b2 {hook_impl.Z40}\n'
+        stdin = line.encode()
+        ns = hook_impl._run_ns('pre-push', False, args, stdin)
+
+    assert ns is None
+
+
 def test_pushing_orphan_branch(push_example):
     src, src_head, clone, _ = push_example