diff --git a/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix b/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
index adf7d75ed5f..c708fa56ef7 100644
--- a/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
+++ b/pkgs/applications/editors/emacs/elisp-packages/elpa-packages.nix
@@ -66,7 +66,7 @@ self: let
         # actually unpack source of ada-mode and wisi
         # which are both needed to compile the tools
         # we need at runtime
-        phases = "unpackPhase " + old.phases; # not a list, interestingly…
+        dontUnpack = false;
         srcs = [
           super.ada-mode.src
           # ada-mode needs a specific version of wisi, check NEWS or ada-mode's
diff --git a/pkgs/build-support/emacs/elpa.nix b/pkgs/build-support/emacs/elpa.nix
index 08257ff2542..f7027dc499d 100644
--- a/pkgs/build-support/emacs/elpa.nix
+++ b/pkgs/build-support/emacs/elpa.nix
@@ -21,7 +21,7 @@ in
 
 import ./generic.nix { inherit lib stdenv emacs texinfo writeText gcc; } ({
 
-  phases = "installPhase fixupPhase distPhase";
+  dontUnpack = true;
 
   installPhase = ''
     runHook preInstall