diff --git a/python/mxnet/gluon/data/dataloader.py b/python/mxnet/gluon/data/dataloader.py
index 10de86099d04..68412267da6b 100644
--- a/python/mxnet/gluon/data/dataloader.py
+++ b/python/mxnet/gluon/data/dataloader.py
@@ -572,6 +572,7 @@ def __init__(self, dataset, batch_size=None, shuffle=False, sampler=None,
         self._pin_device_id = pin_device_id
         self._thread_pool = thread_pool
         self._timeout = timeout
+        assert timeout > 0, "timeout must be positive, given {}".format(timeout)
 
         if batch_sampler is None:
             if batch_size is None: