diff --git a/tests/runtests.pl b/tests/runtests.pl
index a498963d027c1edb4020671dd3c71635311077eb..9a0c0714db71a6e99e6403e1b6cc099916db22bc 100755
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -308,7 +308,7 @@ $SIG{TERM} = \&catch_zap;
 # to prevent them to interfere with our testing!
 
 my $protocol;
-foreach $protocol (('ftp', 'http', 'ftps', 'https', 'no')) {
+foreach $protocol (('ftp', 'http', 'ftps', 'https', 'no', 'all')) {
     my $proxy = "${protocol}_proxy";
     # clear lowercase version
     delete $ENV{$proxy} if($ENV{$proxy});