diff --git a/lambda-events/Cargo.toml b/lambda-events/Cargo.toml
index b8d34055..4e9b4f79 100644
--- a/lambda-events/Cargo.toml
+++ b/lambda-events/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
 name = "aws_lambda_events"
 version = "0.16.0"
+rust-version = "1.81.0"
 description = "AWS Lambda event definitions"
 authors = [
   "Christian Legnitto <christian@legnitto.com>",
diff --git a/lambda-extension/Cargo.toml b/lambda-extension/Cargo.toml
index 16b6dace..37c5ee2d 100644
--- a/lambda-extension/Cargo.toml
+++ b/lambda-extension/Cargo.toml
@@ -2,6 +2,7 @@
 name = "lambda-extension"
 version = "0.11.0"
 edition = "2021"
+rust-version = "1.81.0"
 authors = [
     "David Calavera <dcalaver@amazon.com>",
     "Harold Sun <sunhua@amazon.com>",
diff --git a/lambda-http/Cargo.toml b/lambda-http/Cargo.toml
index 46198dca..4f5ce78c 100644
--- a/lambda-http/Cargo.toml
+++ b/lambda-http/Cargo.toml
@@ -6,6 +6,7 @@ authors = [
     "Harold Sun <sunhua@amazon.com>",
 ]
 edition = "2021"
+rust-version = "1.81.0"
 description = "Application Load Balancer and API Gateway event types for AWS Lambda"
 keywords = ["AWS", "Lambda", "APIGateway", "ALB", "API"]
 license = "Apache-2.0"
diff --git a/lambda-integration-tests/Cargo.toml b/lambda-integration-tests/Cargo.toml
index ee44a969..d7c91088 100644
--- a/lambda-integration-tests/Cargo.toml
+++ b/lambda-integration-tests/Cargo.toml
@@ -3,6 +3,7 @@ name = "aws_lambda_rust_integration_tests"
 version = "0.1.0"
 authors = ["Maxime David"]
 edition = "2021"
+rust-version = "1.81.0"
 description = "AWS Lambda Runtime integration tests"
 license = "Apache-2.0"
 repository = "https://github.com/awslabs/aws-lambda-rust-runtime"
diff --git a/lambda-runtime-api-client/Cargo.toml b/lambda-runtime-api-client/Cargo.toml
index 57fc4bca..d027f0cd 100644
--- a/lambda-runtime-api-client/Cargo.toml
+++ b/lambda-runtime-api-client/Cargo.toml
@@ -2,6 +2,7 @@
 name = "lambda_runtime_api_client"
 version = "0.11.1"
 edition = "2021"
+rust-version = "1.81.0"
 authors = [
     "David Calavera <dcalaver@amazon.com>",
     "Harold Sun <sunhua@amazon.com>",
diff --git a/lambda-runtime/Cargo.toml b/lambda-runtime/Cargo.toml
index 5cf67ae2..fd5144c4 100644
--- a/lambda-runtime/Cargo.toml
+++ b/lambda-runtime/Cargo.toml
@@ -7,6 +7,7 @@ authors = [
 ]
 description = "AWS Lambda Runtime"
 edition = "2021"
+rust-version = "1.81.0"
 license = "Apache-2.0"
 repository = "https://github.com/awslabs/aws-lambda-rust-runtime"
 categories = ["web-programming::http-server"]