diff --git a/SecureEncoderFlask/requirements.txt b/SecureEncoderFlask/requirements.txt
index e282724..9e4e63e 100644
--- a/SecureEncoderFlask/requirements.txt
+++ b/SecureEncoderFlask/requirements.txt
@@ -5,7 +5,7 @@ Flask==3.1.0
 Flask_Cors==5.0.0
 flask_expects_json==1.7.0
 flask_sqlalchemy==3.1.1
-marshmallow==3.23.2
+marshmallow==4.0.0
 marshmallow_sqlalchemy==1.1.0
 Faker==33.1.0
 pytest==8.3.4