diff --git a/pkgs/build-support/emacs/melpa.nix b/pkgs/build-support/emacs/melpa.nix
index 83654cf47144..85bc8aa37b3a 100644
--- a/pkgs/build-support/emacs/melpa.nix
+++ b/pkgs/build-support/emacs/melpa.nix
@@ -40,8 +40,8 @@ import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; } ({
     src = fetchFromGitHub {
       owner = "melpa";
       repo = "package-build";
-      rev = "c48aa078c01b4f07b804270c4583a0a58ffea1c0";
-      sha256 = "sha256-MzPj375upIiYXdQR+wWXv3A1zMqbSrZlH0taLuxx/1M=";
+      rev = "c3c535e93d9dc92acd21ebc4b15016b5c3b90e7d";
+      sha256 = "17z0wbqdd6fspbj43yq8biff6wfggk74xgnaf1xx6ynsp1i74is5";
     };
 
     patches = [ ./package-build-dont-use-mtime.patch ];
diff --git a/pkgs/build-support/emacs/melpa2nix.el b/pkgs/build-support/emacs/melpa2nix.el
index 3de77dbf5e5c..72667dea652c 100644
--- a/pkgs/build-support/emacs/melpa2nix.el
+++ b/pkgs/build-support/emacs/melpa2nix.el
@@ -11,22 +11,22 @@
 ;; Allow installing package tarfiles larger than 10MB
 (setq large-file-warning-threshold nil)
 
-(defun melpa2nix-build-package-1 (rcp)
-  (let* ((default-directory (package-recipe--working-tree rcp)))
+(defun melpa2nix-build-package-1 (rcp version commit)
+  (let ((source-dir (package-recipe--working-tree rcp)))
     (unwind-protect
         (let ((files (package-build-expand-files-spec rcp t)))
-          (unless files
-            (error "Unable to find files matching recipe patterns"))
-          (if (> (length files) 1)
-              (package-build--build-multi-file-package rcp files)
-            (package-build--build-single-file-package rcp files))))))
+          (cond
+           ((= (length files) 1)
+            (package-build--build-single-file-package
+             rcp version commit files source-dir))
+           ((> (length files) 1)
+            (package-build--build-multi-file-package
+             rcp version commit files source-dir))
+           (t (error "Unable to find files matching recipe patterns")))))))
 
 (defun melpa2nix-build-package ()
-  (unless noninteractive
-    (error "`melpa2nix-build-package' is to be used only with -batch"))
+  (if (not noninteractive)
+      (error "`melpa2nix-build-package' is to be used only with -batch"))
   (pcase command-line-args-left
     (`(,package ,version ,commit)
-     (let ((recipe (package-recipe-lookup package)))
-       (setf (oref recipe commit) commit)
-       (setf (oref recipe version) version)
-       (melpa2nix-build-package-1 recipe)))))
+     (melpa2nix-build-package-1 (package-recipe-lookup package) version commit))))
diff --git a/pkgs/build-support/emacs/package-build-dont-use-mtime.patch b/pkgs/build-support/emacs/package-build-dont-use-mtime.patch
index 1ace7771ea3a..fe94de57a300 100644
--- a/pkgs/build-support/emacs/package-build-dont-use-mtime.patch
+++ b/pkgs/build-support/emacs/package-build-dont-use-mtime.patch
@@ -1,21 +1,40 @@
 diff --git a/package-build.el b/package-build.el
-index 29cdb61..c19be1b 100644
+index e572045..9eb0f82 100644
 --- a/package-build.el
 +++ b/package-build.el
-@@ -923,7 +923,6 @@ DIRECTORY is a temporary directory that contains the directory
- that is put in the tarball."
-   (let* ((name (oref rcp name))
-          (version (oref rcp version))
--         (time (oref rcp time))
-          (tar (expand-file-name (concat name "-" version ".tar")
-                                 package-build-archive-dir))
-          (dir (concat name "-" version)))
-@@ -939,7 +938,7 @@ that is put in the tarball."
-        ;; prevent a reproducible tarball as described at
+@@ -415,7 +415,7 @@ (defun package-build--write-pkg-file (desc dir)
+       (princ ";; Local Variables:\n;; no-byte-compile: t\n;; End:\n"
+              (current-buffer)))))
+ 
+-(defun package-build--create-tar (name version directory mtime)
++(defun package-build--create-tar (name version directory)
+   "Create a tar file containing the contents of VERSION of package NAME.
+ DIRECTORY is a temporary directory that contains the directory
+ that is put in the tarball.  MTIME is used as the modification
+@@ -434,7 +434,7 @@ (defun package-build--create-tar (name version directory mtime)
+        ;; prevent a reproducable tarball as described at
         ;; https://reproducible-builds.org/docs/archives.
         "--sort=name"
--       (format "--mtime=@%d" time)
+-       (format "--mtime=@%d" mtime)
 +       "--mtime=@0"
         "--owner=0" "--group=0" "--numeric-owner"
         "--pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime"))
      (when (and package-build-verbose noninteractive)
+@@ -848,12 +848,11 @@ (defun package-build--build-multi-file-package (rcp version commit files source-
+                            (package-build--desc-from-library
+                             name version commit files 'tar)
+                            (error "%s[-pkg].el matching package name is missing"
+-                                  name))))
+-               (mtime (package-build--get-commit-time rcp commit)))
++                                  name)))))
+           (package-build--copy-package-files files source-dir target)
+           (package-build--write-pkg-file desc target)
+           (package-build--generate-info-files files source-dir target)
+-          (package-build--create-tar name version tmp-dir mtime)
++          (package-build--create-tar name version tmp-dir)
+           (package-build--write-pkg-readme name files source-dir)
+           (package-build--write-archive-entry desc))
+       (delete-directory tmp-dir t nil))))
+-- 
+2.37.2
+