diff --git a/artiq-fast.nix b/artiq-fast.nix
index 6529994..b2f2923 100644
--- a/artiq-fast.nix
+++ b/artiq-fast.nix
@@ -1,5 +1,5 @@
 let
-  pkgs = import <nixpkgs> {};
+  pkgs = import <nixpkgs> { overlays = [ (import ./artiq-fast/mozilla-overlay.nix) ]; };
   artiqSrc = <artiqSrc>;
   generatedNix = pkgs.runCommand "generated-nix" { buildInputs = [ pkgs.nix pkgs.git ]; }
     # keep in sync with artiq-fast/pkgs/artiq-version.nix
diff --git a/artiq-full.nix b/artiq-full.nix
index e3d3629..06edece 100644
--- a/artiq-full.nix
+++ b/artiq-full.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {}
+{ pkgs ? import <nixpkgs> { overlays = [ (import ./artiq-fast/mozilla-overlay.nix) ]; }
 , a6p ? <a6p>
 }: