diff --git a/pkgs/build-support/build-mozilla-mach/default.nix b/pkgs/build-support/build-mozilla-mach/default.nix
index 566d1f1a3a75..1132b07930e3 100644
--- a/pkgs/build-support/build-mozilla-mach/default.nix
+++ b/pkgs/build-support/build-mozilla-mach/default.nix
@@ -16,6 +16,7 @@
   extraPostPatch ? "",
   extraNativeBuildInputs ? [ ],
   extraConfigureFlags ? [ ],
+  extraPreConfigure ? "",
   extraBuildInputs ? [ ],
   extraMakeFlags ? [ ],
   extraPassthru ? { },
@@ -470,7 +471,8 @@ buildStdenv.mkDerivation {
     # linking firefox hits the vm.max_map_count kernel limit with the default musl allocator
     # TODO: Default vm.max_map_count has been increased, retest without this
     export LD_PRELOAD=${mimalloc}/lib/libmimalloc.so
-  '';
+  ''
+  + extraPreConfigure;
 
   # firefox has a different definition of configurePlatforms from nixpkgs, see configureFlags
   configurePlatforms = [ ];
diff --git a/pkgs/by-name/li/librewolf-unwrapped/librewolf.nix b/pkgs/by-name/li/librewolf-unwrapped/librewolf.nix
index 1e3bf61a2e63..dca96ea94fb5 100644
--- a/pkgs/by-name/li/librewolf-unwrapped/librewolf.nix
+++ b/pkgs/by-name/li/librewolf-unwrapped/librewolf.nix
@@ -24,6 +24,10 @@ rec {
     "--enable-lto=thin,cross"
   ];
 
+  extraPreConfigure = ''
+    export MOZ_TELEMETRY_REPORTING=
+  '';
+
   extraPostPatch = ''
     while read patch_name; do
       echo "applying LibreWolf patch: $patch_name"
diff --git a/pkgs/by-name/li/librewolf-unwrapped/package.nix b/pkgs/by-name/li/librewolf-unwrapped/package.nix
index 2dcab94afe52..86076f9126aa 100644
--- a/pkgs/by-name/li/librewolf-unwrapped/package.nix
+++ b/pkgs/by-name/li/librewolf-unwrapped/package.nix
@@ -20,6 +20,7 @@ in
   branding = "browser/branding/librewolf";
   inherit (librewolf-src)
     extraConfigureFlags
+    extraPreConfigure
     extraPatches
     extraPostPatch
     extraPassthru