diff --git a/pydu/cmd.pyi b/pydu/cmd.pyi
new file mode 100644
index 0000000..76fe647
--- /dev/null
+++ b/pydu/cmd.pyi
@@ -0,0 +1,4 @@
+class TimeoutExpired(Exception):
+
+    def __init__(self, cmd: str, timeout: int, output: str, stderr: str) -> None: ...
+