diff --git a/mirror-channel.pl b/mirror-channel.pl
index 269877f..153b149 100644
--- a/mirror-channel.pl
+++ b/mirror-channel.pl
@@ -4,7 +4,6 @@
 
 use strict;
 use Nix::Manifest;
-use Nix::GeneratePatches;
 use Nix::Utils;
 use Nix::Store;
 use File::Basename;
@@ -15,7 +14,7 @@ use Forks::Super 'bg_eval';
 
 
 if (scalar @ARGV < 4 || scalar @ARGV > 6) {
-    print STDERR "Syntax: perl mirror-channel.pl <src-channel-url> <dst-channel-dir> <bucket-name> <nar-url> [<all-patches-manifest [<nix-exprs-url>]]\n";
+    print STDERR "Syntax: perl mirror-channel.pl <src-channel-url> <dst-channel-dir> <bucket-name> <nar-url> [<nix-exprs-url>]\n";
     exit 1;
 }
 
@@ -27,8 +26,7 @@ my $srcChannelURL = $ARGV[0];
 my $dstChannelPath = $ARGV[1];
 my $bucketName = $ARGV[2];
 my $cacheURL = $ARGV[3]; die if $cacheURL =~ /\/$/;
-my $allPatchesManifest = $ARGV[4] || "";
-my $nixexprsURL = $ARGV[5];
+my $nixexprsURL = $ARGV[4];
 
 die "$dstChannelPath doesn't exist\n" unless -d $dstChannelPath;
 
@@ -206,16 +204,5 @@ foreach my $r (@results) {
 }
 
 
-# Read all the old patches and propagate the useful ones.  We use the
-# file "all-patches" to keep track of all patches that have been
-# generated in the past, so that patches are not lost if (for
-# instance) a package temporarily disappears from the source channel,
-# or if multiple instances of this script are running concurrently.
-my (%dummy, %allPatches);
-readManifest($allPatchesManifest, \%dummy, \%allPatches)
-    if $allPatchesManifest ne "" && -f $allPatchesManifest;
-propagatePatches \%allPatches, \%narFiles, \%patches;
-
-
 # Make the temporary manifest available.
 writeManifest("$dstChannelPath/MANIFEST", \%narFiles, \%patches);
diff --git a/mirror-nixos-branch.sh b/mirror-nixos-branch.sh
index 68998be..412db28 100755
--- a/mirror-nixos-branch.sh
+++ b/mirror-nixos-branch.sh
@@ -60,7 +60,7 @@ else
 
     perl -w ./mirror-channel.pl "$url/channel" "$tmpDir" \
         nix-cache http://cache.nixos.org \
-        /data/releases/patches/all-patches "$url/job/nixos.channel/download/1"
+        "$url/job/nixos.channel/download/1"
 
     # Generate the programs.sqlite database and put it in nixexprs.tar.xz.
     mkdir $tmpDir/unpack
diff --git a/mirror-nixpkgs.sh b/mirror-nixpkgs.sh
index 486321a..0252549 100755
--- a/mirror-nixpkgs.sh
+++ b/mirror-nixpkgs.sh
@@ -31,7 +31,7 @@ else
 
     perl -w ./mirror-channel.pl "$url/channel" "$tmpDir" \
         nix-cache http://cache.nixos.org \
-        /data/releases/patches/all-patches "$url/job/tarball/download/1"
+        "$url/job/tarball/download/1"
 
     # Extract the manual.
     $curl -L $url/job/manual/output/out | bzip2 -d | nix-store --restore $tmpDir/foo