diff --git a/pkgs/build-support/emacs/generic.nix b/pkgs/build-support/emacs/generic.nix
index d41f90ebd05d..6fa27f098392 100644
--- a/pkgs/build-support/emacs/generic.nix
+++ b/pkgs/build-support/emacs/generic.nix
@@ -32,8 +32,11 @@ stdenv.mkDerivation ({
   unpackCmd = ''
     case "$curSrc" in
       *.el)
-        cp $curSrc $pname.el
-        chmod +w $pname.el
+        # keep original source filename without the hash
+        local filename=$(basename "$curSrc")
+        filename="''${filename:33}"
+        cp $curSrc $filename
+        chmod +w $filename
         sourceRoot="."
         ;;
       *)