diff --git a/sys/src/cmd/ptrap.c b/sys/src/cmd/ptrap.c
index f7b43515d..30a4db07f 100644
--- a/sys/src/cmd/ptrap.c
+++ b/sys/src/cmd/ptrap.c
@@ -372,4 +372,6 @@ threadmain(int argc, char **argv)
 		filters = f;
 	}
 	threadpostmountsrv(&ptrapsrv, nil, "/mnt/plumb", MREPL | MCREATE);
+
+	threadexits(nil);
 }