diff --git a/pyproject.toml b/pyproject.toml
index 8fee45c5..42d02f63 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -35,7 +35,7 @@ test = [
     'astropy >= 5.0.4',
     'gwcs',
     'packaging>=16.0',
-    'jsonschema<4.18',
+    'jsonschema<4.21',
 ]
 
 [project.urls]