diff --git a/pyproject.toml b/pyproject.toml
index c572fde..d89728e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,7 @@ classifiers = [
 dependencies = [
   "jsonschema>=4.4.0",
   "fastjsonschema>=2.16.2",
-  "raillabel>=3.1.0",
+  "raillabel>=3.1.0, <4.0.0",
   "pyyaml>=6.0.0"
 ]