diff --git a/pkgs/development/python-modules/beanquery/default.nix b/pkgs/development/python-modules/beanquery/default.nix
index f1dad530cbc2..198061c736cf 100644
--- a/pkgs/development/python-modules/beanquery/default.nix
+++ b/pkgs/development/python-modules/beanquery/default.nix
@@ -7,18 +7,20 @@
   python-dateutil,
   pytestCheckHook,
   setuptools,
-  tatsu,
+  tatsu-lts,
 }:
-buildPythonPackage rec {
+buildPythonPackage {
   pname = "beanquery";
-  version = "0.1.0";
+  version = "0.1.0-unstable-2025-01-10";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "beancount";
     repo = "beanquery";
-    tag = "v${version}";
-    hash = "sha256-1+KTUvnqPceRbzY1OZwOSQdK7f78K9kSwtQfI1SUIa8=";
+    # Pinned at commit where tatsu dependency replaced with tatsu-lts
+    # Later snapsot versions break fava build due to API changes at beanquery/shell.py
+    rev = "e77a67996a54eef2e9d77b6352c74a40164e281d";
+    hash = "sha256-XYfKAscm55lY4YjIGTQ6RMFnCPWemfszpheGQ9qjMiM=";
   };
 
   build-system = [ setuptools ];
@@ -27,15 +29,12 @@ buildPythonPackage rec {
     beancount
     click
     python-dateutil
-    tatsu
+    tatsu-lts
   ];
 
-  pythonRelaxDeps = [ "tatsu" ];
-
   nativeCheckInputs = [ pytestCheckHook ];
 
   pythonImportsCheck = [
-    "beancount"
     "beanquery"
   ];