diff --git a/sys/dev/nvme/nvme_ns_cmd.c b/sys/dev/nvme/nvme_ns_cmd.c
index 5cf61b772fed..1bf92ec5e02a 100644
--- a/sys/dev/nvme/nvme_ns_cmd.c
+++ b/sys/dev/nvme/nvme_ns_cmd.c
@@ -191,6 +191,14 @@ nvme_ns_dump(struct nvme_namespace *ns, void *virt, off_t offset, size_t len)
 		nvme_qpair_process_completions(req->qpair);
 	}
 
+	/*
+	 * Normally, when using the polling interface, we can't return a
+	 * timeout error because we don't know when the completion routines
+	 * will be called if the command later completes. However, in this
+	 * case we're running a system dump, so all interrupts are turned
+	 * off, the scheduler isn't running so there's nothing to complete
+	 * the transaction.
+	 */
 	if (status.done == FALSE)
 		return (ETIMEDOUT);