diff --git a/README.md b/README.md
index 1806c25..c4fb71a 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ https://aws.amazon.com/about-aws/whats-new/2023/09/amazon-route-53-managed-prefi
 
 The CloudFormation template `cloudformation/template.yml` creates a stack with the following resources:
 
-1. AWS Lambda function with customizable config file called `services.json`. The function's code is in `lambda/update_aws_ip_ranges.py` and is written in Python compatible with version 3.10.
+1. AWS Lambda function with customizable config file called `services.json`. The function's code is in `lambda/update_aws_ip_ranges.py` and is written in Python compatible with version 3.12.
 1. Lambda function's execution role.
 1. SNS subscription and Lambda invocation permissions for the `arn:aws:sns:us-east-1:806199016981:AmazonIpSpaceChanged` SNS topic.
 
diff --git a/cloudformation/template.yml b/cloudformation/template.yml
index ad199b2..4572eac 100644
--- a/cloudformation/template.yml
+++ b/cloudformation/template.yml
@@ -29,7 +29,7 @@ Resources:
       Handler: 'update_aws_ip_ranges.lambda_handler'
       MemorySize: 256
       Role: !GetAtt 'LambdaUpdateIPRangesIamRole.Arn'
-      Runtime: python3.11
+      Runtime: python3.12
       Timeout: 300
       ReservedConcurrentExecutions: 2
       Code:
diff --git a/terraform/main.tf b/terraform/main.tf
index edc9ed7..c955aa4 100644
--- a/terraform/main.tf
+++ b/terraform/main.tf
@@ -275,7 +275,7 @@ resource "aws_lambda_function" "update_ip_ranges" {
   description                    = "This Lambda function, invoked by an incoming SNS message, updates the IPv4 and IPv6 ranges with the addresses from the specified services"
   role                           = aws_iam_role.update_ip_ranges.arn
   handler                        = "update_aws_ip_ranges.lambda_handler"
-  runtime                        = "python3.11"
+  runtime                        = "python3.12"
   timeout                        = 300
   reserved_concurrent_executions = 2
   memory_size                    = 256