diff --git a/Makefile b/Makefile
index f8442eab0..14950613b 100644
--- a/Makefile
+++ b/Makefile
@@ -399,6 +399,7 @@ test:
 	done
 
 .PHONY: ktest
+ktest: CONSOLE = ttyS0
 ktest: initramfs $(CARGO_OSDK)
 	@# Notes:
 	@# 1. linux-bzimage-setup is excluded from ktest since it's hard to be unit tested;