diff --git a/contrib/scripts/install_prereq b/contrib/scripts/install_prereq
index c3217033db..9215132044 100755
--- a/contrib/scripts/install_prereq
+++ b/contrib/scripts/install_prereq
@@ -261,7 +261,7 @@ check_installed_zypper() {
 
 handle_debian() {
 	if ! [ -x "$(command -v aptitude)" ]; then
-		apt-get install aptitude
+		apt-get install -y aptitude
 	fi
 	extra_packs=`check_installed_debs $PACKAGES_DEBIAN`
 	$testcmd aptitude update