diff --git a/lib/scripts/prefTest.pl.in b/lib/scripts/prefTest.pl.in
index 4e0aab739f..d999b6a10b 100755
--- a/lib/scripts/prefTest.pl.in
+++ b/lib/scripts/prefTest.pl.in
@@ -30,6 +30,8 @@ my %allowedKeys = (
   "use_converter_needauth_forbidden" => ["true", "false"],
   "use_converter_needauth" => ["true", "false"],
   "allow_geometry_session" => ["false"],
+  "use_converter_cache" => ["true", "false"],
+  "converter_cache_maxage" => "integer",
     );
 
 my %Converter = ();
@@ -53,14 +55,20 @@ if ($handle_argv eq "test") {
   @ctestpars = &getSubstitutes(\%allowedKeys, \%Subst,
 			       "allow_geometry_session=false",
 			       "use_converter_needauth_forbidden=false",
-			       "use_converter_needauth=false", @ARGV);
+			       "use_converter_needauth=false",
+			       "use_converter_cache=false",
+			       "converter_cache_maxage=" . 180*24*60*60,
+			       @ARGV);
 }
 elsif ($handle_argv eq "default") {
   $shell_escapes = 0;
   @ctestpars = &getSubstitutes(\%allowedKeys, \%Subst,
 			       "allow_geometry_session=false",
 			       "use_converter_needauth_forbidden=true",
-			       "use_converter_needauth=true", @ARGV);
+			       "use_converter_needauth=true",
+			       "use_converter_cache=true",
+			       "converter_cache_maxage=" . 61*24*60*60,
+			       @ARGV);
 }
 else {
   @ctestpars = &getSubstitutes(\%allowedKeys, \%Subst,
diff --git a/lib/scripts/prefTest.pm b/lib/scripts/prefTest.pm
index 814304fa50..8f88769134 100644
--- a/lib/scripts/prefTest.pm
+++ b/lib/scripts/prefTest.pm
@@ -31,12 +31,22 @@ sub getSubstitutes($$@)
 	my $value = $2;
 	my $valid = 0;
 	if (defined($rAllowedKeys->{$key})) {
-	  for my $val (@{$rAllowedKeys->{$key}}) {
-	    if ($val eq $value) {
-	      $valid = 1;
-	      last;
+	  if (ref($rAllowedKeys->{$key}) eq "ARRAY") {
+	    for my $val (@{$rAllowedKeys->{$key}}) {
+	      if ($val eq $value) {
+		$valid = 1;
+		last;
+	      }
 	    }
 	  }
+	  elsif ($rAllowedKeys->{$key} eq "integer") {
+	    if ($value =~ /^\d+$/) {
+	      $valid = 1;
+	    }
+	  }
+	  elsif ($rAllowedKeys->{$key} eq "string") {
+	    $valid = 1;
+	  }
 	}
 	if ($valid) {
 	  $rSubst->{$key} = [$value, 0];
@@ -82,15 +92,15 @@ sub getConverter($$)
   return undef if ($to !~ /^((dvi3?|pdf[23456]?)(log)?)$/);
   ($l, $cmd) = getNext($l);
   if ($add) {
-    if ($cmd !~ /\-shell-escape/) {
+    if ($cmd !~ /\-shell-(escape|restricted)/) {
       if ($cmd =~ /^(\S+)\s*(.*)$/) {
-	$cmd = "$1 -shell-escape $2";
+	$cmd = "$1 -shell-restricted $2";
 	$cmd =~ s/\s+$//;
       }
     }
   }
   else {
-    $cmd =~ s/\s+\-shell\-escape//;
+    $cmd =~ s/\s+\-shell\-(escape|restricted)//;
   }
   ($l, $par) = getNext($l);
   return undef if ($par !~ /^latex/);