diff --git a/scripts/nix-pull.in b/scripts/nix-pull.in
index 8d5db2f57c..e59a38eec7 100755
--- a/scripts/nix-pull.in
+++ b/scripts/nix-pull.in
@@ -49,6 +49,8 @@ sub processURL {
 
     my $manifest;
 
+    my $origUrl = $ENV{'NIX_ORIG_URL'} || $url;
+
     # First see if a bzipped manifest is available.
     if (system("$Nix::Config::curl --fail --silent --location --head '$url'.bz2 > /dev/null") == 0) {
         print "fetching list of Nix archives at `$url.bz2'...\n";
@@ -72,7 +74,7 @@ sub processURL {
 
     my $urlFile = "$manifestDir/$baseName-$hash.url";
     open URL, ">$urlFile" or die "cannot create `$urlFile'";
-    print URL ($ENV{'NIX_ORIG_URL'} || $url);
+    print URL $origUrl;
     close URL;
     
     my $finalPath = "$manifestDir/$baseName-$hash.nixmanifest";
@@ -89,7 +91,7 @@ sub processURL {
         my $url2 = <URL>;
         chomp $url2;
         close URL;
-        next unless $url eq $url2;
+        next unless $origUrl eq $url2;
         my $base = $urlFile2; $base =~ s/.url$//;
         unlink "${base}.url";
         unlink "${base}.nixmanifest";