diff --git a/pyproject.toml b/pyproject.toml
index 1cb581c9..f56589fc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -52,7 +52,7 @@ Tracker = "https://github.com/common-workflow-language/user_guide/issues"
 [project.optional-dependencies]
 test = [
     "cwltest==2.*",
-    "cwltool==3.1.*",
+    "cwltool>=3.1,<3.3",
 ]
 watch = ["sphinx-autobuild==2024.10.*"]
 rtd = ["udocker"]