diff --git a/pyproject.toml b/pyproject.toml
index 67ed5528..e3d3f952 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -78,7 +78,7 @@
     tests = [
         "pytest-cov==5.0.0",
         "pytest==8.3.3",
-        "tox==4.18.1",
+        "tox==4.21.1",
         "python-dotenv==1.0.1",
     ]
     tools = ["pyperclip==1.9.0"]