diff --git a/pkgs/by-name/fi/firefly-iii/package.nix b/pkgs/by-name/fi/firefly-iii/package.nix
index d1f35cba4f03..4fb02d0e786b 100644
--- a/pkgs/by-name/fi/firefly-iii/package.nix
+++ b/pkgs/by-name/fi/firefly-iii/package.nix
@@ -1,6 +1,7 @@
 {
   lib,
   fetchFromGitHub,
+  fetchzip,
   stdenvNoCC,
   nodejs-slim,
   fetchNpmDeps,
@@ -10,13 +11,20 @@
   nix-update-script,
   dataDir ? "/var/lib/firefly-iii",
 }:
-
 let
   php = php85;
+  version = "6.6.2";
+
+  # Release tarball contains translations downloaded from crowdin
+  releaseTarball = fetchzip {
+    url = "https://github.com/firefly-iii/firefly-iii/releases/download/v${version}/FireflyIII-v${version}.tar.gz";
+    stripRoot = false;
+    hash = "sha256-vPuLCjU8MzV5odoDl9QQXj4kKnT6QBSAPwvekMxJtEM=";
+  };
 in
 stdenvNoCC.mkDerivation (finalAttrs: {
   pname = "firefly-iii";
-  version = "6.6.2";
+  inherit version;
 
   src = fetchFromGitHub {
     owner = "firefly-iii";
@@ -55,6 +63,7 @@ stdenvNoCC.mkDerivation (finalAttrs: {
   '';
 
   passthru = {
+    inherit releaseTarball;
     phpPackage = php;
     tests = nixosTests.firefly-iii;
     updateScript = nix-update-script {
@@ -68,6 +77,10 @@ stdenvNoCC.mkDerivation (finalAttrs: {
   postInstall = ''
     chmod -R u+w $out/share
     mv $out/share/php/firefly-iii/* $out/
+
+    # Copy language files from release tarball (contains all translations)
+    cp -r ${finalAttrs.passthru.releaseTarball}/resources/lang/* $out/resources/lang/
+
     rm -R $out/share $out/storage $out/bootstrap/cache $out/node_modules
     ln -s ${dataDir}/storage $out/storage
     ln -s ${dataDir}/cache $out/bootstrap/cache