diff --git a/images/lib.sh b/images/lib.sh
index 2967feb..b690a7c 100644
--- a/images/lib.sh
+++ b/images/lib.sh
@@ -40,8 +40,8 @@ debootstrap() {
 }
 
 upgrade_debs() {
-    do_in_target apt-get update
-    do_in_target apt-get -y upgrade
+    do_in_target "apt-get update"
+    do_in_target "apt-get -y upgrade"
 }
 
 secondstage() {