diff --git a/er_aws_rds/rds.py b/er_aws_rds/rds.py
index c86b9db..c380005 100644
--- a/er_aws_rds/rds.py
+++ b/er_aws_rds/rds.py
@@ -110,6 +110,8 @@ def _password(self) -> None:
             self,
             id=f"{self.data.identifier}-password",
             length=20,
+            # MasterUserPassword Constraints in https://docs.aws.amazon.com/AmazonRDS/latest/APIReference/API_CreateDBInstance.html
+            override_special="!#$%*()-_=+[]{}<>:?",
             min_special=0,  # need to be 0 to import current password. It should be improved in next version of module once the instaces are imported.
             min_numeric=0,
             keepers={"reset_password": self.data.reset_password or ""},