diff --git a/pyproject.toml b/pyproject.toml
index 3e56b661..fe5ada2d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,7 +34,7 @@ classifiers = [
 dev = [
     "ruff>=0.3,<0.5",
     "build>=1.0,<1.3",
-    "tox>=4.0,<4.15",  # Python test environment manager
+    "tox>=4.0,<4.16",  # Python test environment manager
     "twine>=3.3,<5.1",  # Used to make releases to PyPI
     "types-requests",
 ]