diff --git a/templates/03-efsfilesystem.yaml b/templates/03-efsfilesystem.yaml
index 0ab3981..3c365b1 100644
--- a/templates/03-efsfilesystem.yaml
+++ b/templates/03-efsfilesystem.yaml
@@ -528,7 +528,7 @@ Resources:
       FunctionName: !Join [ '', [ 'efs-', !Ref ElasticFileSystem, '-size-monitor' ] ]
       Handler: index.handler
       Role: !GetAtt LambdaRole.Arn
-      Runtime: python2.7
+      Runtime: python3.9
       Timeout: 60
   LambdaRole:
     Type: AWS::IAM::Role
diff --git a/templates/03-rds.yaml b/templates/03-rds.yaml
index 547e89e..6f1d5b4 100644
--- a/templates/03-rds.yaml
+++ b/templates/03-rds.yaml
@@ -151,7 +151,7 @@ Resources:
       DatabaseName: !Ref DatabaseName
       DBSubnetGroupName: !Ref DataSubnetGroup
       Engine: aurora-postgresql
-      DBClusterParameterGroupName: default.aurora-postgresql11
+      DBClusterParameterGroupName: default.aurora-postgresql12
       KmsKeyId:
         !If [ UseAWS-ManagedCMK, !Ref 'AWS::NoValue', !Ref DatabaseCmk ]
       MasterUsername: !Join ['', ['{{resolve:secretsmanager:', !Ref MyRDSInstanceSecretArn, ':SecretString:username}}' ]]