diff --git a/scripts/nix-copy-closure.in b/scripts/nix-copy-closure.in
index ec2df88289..80a6a80518 100644
--- a/scripts/nix-copy-closure.in
+++ b/scripts/nix-copy-closure.in
@@ -4,8 +4,20 @@ my $binDir = $ENV{"NIX_BIN_DIR"};
 $binDir = "@bindir@" unless defined $binDir;
 
 
+if (scalar @ARGV < 1) {
+    print STDERR <<EOF
+Usage: nix-copy-closure HOSTNAME [--sign] PATHS...
+EOF
+    ;
+    exit 1;
+}
+
+
 # Get the target host.
 my $sshHost = shift @ARGV;
+my @sshOpts = split ' ', $ENV{"NIX_SSHOPTS"};
+
+my $sign = 0;
 
 
 # !!! Copied from nix-pack-closure, should put this in a module.
@@ -14,6 +26,10 @@ my @storePaths = ();
 
 while (@ARGV) {
     my $storePath = shift @ARGV;
+    if ($storePath eq "--sign") {
+        $sign = 1;
+        next;
+    }
 
     # $storePath might be a symlink to the store, so resolve it.
     $storePath = (`$binDir/nix-store --query --resolve '$storePath'`
@@ -38,7 +54,7 @@ while (@ARGV) {
 
 
 # Ask the remote host which paths are invalid.
-open(READ, "-|", "ssh", $sshHost, "nix-store", "--check-validity", "--print-invalid", @storePaths);
+open(READ, "-|", "ssh", @sshOpts, $sshHost, "nix-store", "--check-validity", "--print-invalid", @storePaths);
 my @missing = ();
 while (<READ>) {
     chomp;
@@ -50,6 +66,8 @@ close READ or die;
 
 # Export the store paths and import them on the remote machine.
 if (scalar @missing > 0) {
-    system("nix-store --export @missing | ssh $sshHost nix-store --import") == 0
+    my $extraOpts = "";
+    $extraOpts .= "--sign" if $sign == 1;
+    system("nix-store --export $extraOpts @missing | ssh @sshOpts $sshHost nix-store --import") == 0
         or die "copying store paths to remote machine failed: $?";
 }