diff --git a/software/apt-lib.pl b/software/apt-lib.pl
index 0d342c5e5..ab60271ba 100644
--- a/software/apt-lib.pl
+++ b/software/apt-lib.pl
@@ -10,6 +10,7 @@ sub update_system_install
 {
 local (@rv, @newpacks);
 local $update = $_[0] || $in{'update'};
+$ENV{'DEBIAN_FRONTEND'} = 'noninteractive';
 local $cmd = $apt_get_command eq "apt-get" ?
 	"$apt_get_command -y --force-yes -f install $update" :
 	"$apt_get_command -y -f install $update";
diff --git a/software/debian-lib.pl b/software/debian-lib.pl
index c35ef123c..1c7948d35 100644
--- a/software/debian-lib.pl
+++ b/software/debian-lib.pl
@@ -165,6 +165,7 @@ local $args = ($in->{'depends'} ? " --force-depends" : "").
 	      ($in->{'overwrite'} ? " --force-overwrite" : "").
 	      ($in->{'downgrade'} ? " --force-downgrade" : "");
 local $qm = quotemeta($_[0]);
+$ENV{'DEBIAN_FRONTEND'} = 'noninteractive';
 local $out = &backquote_logged("dpkg --install $args $qm 2>&1 </dev/null");
 if ($?) {
 	return "<pre>$out</pre>";
@@ -177,6 +178,7 @@ return undef;
 sub delete_package
 {
 local $qm = quotemeta($_[0]);
+$ENV{'DEBIAN_FRONTEND'} = 'noninteractive';
 local $out = &backquote_logged("dpkg --remove $qm 2>&1 </dev/null");
 if ($? || $out =~ /which isn.t installed/i) {
 	return "<pre>$out</pre>";