1diff --git a/pre_commit/languages/pygrep.py b/pre_commit/languages/pygrep.py
2index ec55560..44e08a1 100644
3--- a/pre_commit/languages/pygrep.py
4+++ b/pre_commit/languages/pygrep.py
5@@ -98,7 +98,7 @@ def run_hook(
6 color: bool,
7 ) -> tuple[int, bytes]:
8 cmd = (sys.executable, '-m', __name__, *args, entry)
9- return xargs(cmd, file_args, color=color)
10+ return xargs(cmd, file_args, color=color, env={ "PYTHONPATH": ':'.join(sys.path) })
11
12
13 def main(argv: Sequence[str] | None = None) -> int: