diff --git a/pyproject.toml b/pyproject.toml
index f69a80d..a2e098b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,6 +12,7 @@ mutmut = "^2.4.4"
 hypothesis = "^6.99.6"
 install = "^1.3.5"
 httpx = "^0.27.0"
+ujson = "^5.9.0"
 
 
 [build-system]