diff --git a/scripts/copy-from-other-stores.pl.in b/scripts/copy-from-other-stores.pl.in
index b930b7207..92869ee7a 100755
--- a/scripts/copy-from-other-stores.pl.in
+++ b/scripts/copy-from-other-stores.pl.in
@@ -36,42 +36,45 @@ sub findStorePath {
 if ($ARGV[0] eq "--query") {
 
     while (<STDIN>) {
-        my $cmd = $_; chomp $cmd;
+        chomp;
+        my ($cmd, @args) = split " ", $_;
 
         if ($cmd eq "have") {
-            my $storePath = <STDIN>; chomp $storePath;
-            print STDOUT (defined findStorePath($storePath) ? "1\n" : "0\n");
+            foreach my $storePath (@args) {
+                print "$storePath\n" if defined findStorePath($storePath);
+            }
+            print "\n";
         }
 
         elsif ($cmd eq "info") {
-            my $storePath = <STDIN>; chomp $storePath;
-            my ($store, $sourcePath) = findStorePath($storePath);
-            if (!defined $store) {
-                print "0\n";
-                next; # not an error
-            }
-            print "1\n";
+            foreach my $storePath (@args) {
+                my ($store, $sourcePath) = findStorePath($storePath);
+                next unless defined $store;
 
-            $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
+                $ENV{"NIX_DB_DIR"} = "$store/var/nix/db";
             
-            my $deriver = `@bindir@/nix-store --query --deriver $storePath`;
-            die "cannot query deriver of `$storePath'" if $? != 0;
-            chomp $deriver;
-            $deriver = "" if $deriver eq "unknown-deriver";
+                my $deriver = `@bindir@/nix-store --query --deriver $storePath`;
+                die "cannot query deriver of `$storePath'" if $? != 0;
+                chomp $deriver;
+                $deriver = "" if $deriver eq "unknown-deriver";
 
-            my @references = split "\n",
-                `@bindir@/nix-store --query --references $storePath`;
-            die "cannot query references of `$storePath'" if $? != 0;
+                my @references = split "\n",
+                    `@bindir@/nix-store --query --references $storePath`;
+                die "cannot query references of `$storePath'" if $? != 0;
 
-            my $narSize = `@bindir@/nix-store --query --size $storePath`;
-            die "cannot query size of `$storePath'" if $? != 0;
-            chomp $narSize;
+                my $narSize = `@bindir@/nix-store --query --size $storePath`;
+                die "cannot query size of `$storePath'" if $? != 0;
+                chomp $narSize;
 
-            print "$deriver\n";
-            print scalar @references, "\n";
-            print "$_\n" foreach @references;
-            print "$narSize\n";
-            print "$narSize\n";
+                print "$storePath\n";
+                print "$deriver\n";
+                print scalar @references, "\n";
+                print "$_\n" foreach @references;
+                print "$narSize\n";
+                print "$narSize\n";
+            }
+
+            print "\n";
         }
 
         else { die "unknown command `$cmd'"; }
diff --git a/scripts/download-using-manifests.pl.in b/scripts/download-using-manifests.pl.in
index ef663dabb..f00debc68 100755
--- a/scripts/download-using-manifests.pl.in
+++ b/scripts/download-using-manifests.pl.in
@@ -173,56 +173,54 @@ sub computeSmallestDownload {
 if ($ARGV[0] eq "--query") {
 
     while (<STDIN>) {
-        my $cmd = $_; chomp $cmd;
+        chomp;
+        my ($cmd, @args) = split " ", $_;
 
         if ($cmd eq "have") {
-            my $storePath = <STDIN>; chomp $storePath;
-            print STDOUT (
-                scalar @{$dbh->selectcol_arrayref("select 1 from NARs where storePath = ?", {}, $storePath)} > 0
-                ? "1\n" : "0\n");
+            foreach my $storePath (@args) {
+                print "$storePath\n" if scalar @{$dbh->selectcol_arrayref("select 1 from NARs where storePath = ?", {}, $storePath)} > 0;
+            }
+            print "\n";
         }
 
         elsif ($cmd eq "info") {
-            my $storePath = <STDIN>; chomp $storePath;
+            foreach my $storePath (@args) {
 
-            my $infos = $dbh->selectall_arrayref(
-                "select * from NARs where storePath = ?",
-                { Slice => {} }, $storePath);
+                my $infos = $dbh->selectall_arrayref(
+                    "select * from NARs where storePath = ?",
+                    { Slice => {} }, $storePath);
             
-            my $info;
-            if (scalar @{$infos} > 0) {
-                $info = @{$infos}[0];
-            }
-            else {
-                print "0\n";
-                next; # not an error
-            }
+                next unless scalar @{$infos} > 0;
+                my $info = @{$infos}[0];
 
-            print "1\n";
-            print "$info->{deriver}\n";
-            my @references = split " ", $info->{refs};
-            print scalar @references, "\n";
-            print "$_\n" foreach @references;
+                print "$storePath\n";
+                print "$info->{deriver}\n";
+                my @references = split " ", $info->{refs};
+                print scalar @references, "\n";
+                print "$_\n" foreach @references;
 
-            my @path = computeSmallestDownload $storePath;
+                my @path = computeSmallestDownload $storePath;
 
-            my $downloadSize = 0;
-            while (scalar @path > 0) {
-                my $edge = pop @path;
-                my $u = $edge->{start};
-                my $v = $edge->{end};
-                if ($edge->{type} eq "patch") {
-                    $downloadSize += $edge->{info}->{size} || 0;
+                my $downloadSize = 0;
+                while (scalar @path > 0) {
+                    my $edge = pop @path;
+                    my $u = $edge->{start};
+                    my $v = $edge->{end};
+                    if ($edge->{type} eq "patch") {
+                        $downloadSize += $edge->{info}->{size} || 0;
+                    }
+                    elsif ($edge->{type} eq "narfile") {
+                        $downloadSize += $edge->{info}->{size} || 0;
+                    }
                 }
-                elsif ($edge->{type} eq "narfile") {
-                    $downloadSize += $edge->{info}->{size} || 0;
-                }
-            }
 
-            print "$downloadSize\n";
+                print "$downloadSize\n";
             
-            my $narSize = $info->{narSize} || 0;
-            print "$narSize\n";
+                my $narSize = $info->{narSize} || 0;
+                print "$narSize\n";
+            }
+
+            print "\n";
         }
         
         else { die "unknown command `$cmd'"; }
diff --git a/src/libstore/globals.cc b/src/libstore/globals.cc
index f660ed68d..9636bf49d 100644
--- a/src/libstore/globals.cc
+++ b/src/libstore/globals.cc
@@ -155,8 +155,8 @@ void setDefaultsFromEnvironment()
 
     string subs = getEnv("NIX_SUBSTITUTERS", "default");
     if (subs == "default") {
-        //substituters.push_back(nixLibexecDir + "/nix/substituters/copy-from-other-stores.pl");
-        //substituters.push_back(nixLibexecDir + "/nix/substituters/download-using-manifests.pl");
+        substituters.push_back(nixLibexecDir + "/nix/substituters/copy-from-other-stores.pl");
+        substituters.push_back(nixLibexecDir + "/nix/substituters/download-using-manifests.pl");
         substituters.push_back(nixLibexecDir + "/nix/substituters/download-from-binary-cache.pl");
     } else
         substituters = tokenizeString(subs, ":");