diff --git a/pyproject.toml b/pyproject.toml
index b4a2653..f9a0df5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
 ]
 dependencies = [
-    "marshmallow==3.20.1",
+    "marshmallow==3.21.2",
 ]
 
 [project.optional-dependencies]