diff --git a/packages/@aws-cdk/aws-ecs/test/ec2/integ.environment-file.expected.json b/packages/@aws-cdk/aws-ecs/test/ec2/integ.environment-file.expected.json
index b26608d3626bf..eee0801d80061 100644
--- a/packages/@aws-cdk/aws-ecs/test/ec2/integ.environment-file.expected.json
+++ b/packages/@aws-cdk/aws-ecs/test/ec2/integ.environment-file.expected.json
@@ -1267,7 +1267,7 @@
             "Ref": "EnvFileDeploymentAwsCliLayerA8FC897D"
           }
         ],
-        "Runtime": "python3.6",
+        "Runtime": "python3.7",
         "Timeout": 900
       },
       "DependsOn": [
diff --git a/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts b/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
index 439af53a90dd9..8e25826647a64 100644
--- a/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
+++ b/packages/@aws-cdk/aws-s3-deployment/lib/bucket-deployment.ts
@@ -278,7 +278,7 @@ export class BucketDeployment extends CoreConstruct {
       uuid: this.renderSingletonUuid(props.memoryLimit, props.vpc),
       code: lambda.Code.fromAsset(path.join(__dirname, 'lambda')),
       layers: [new AwsCliLayer(this, 'AwsCliLayer')],
-      runtime: lambda.Runtime.PYTHON_3_6,
+      runtime: lambda.Runtime.PYTHON_3_7,
       environment: props.useEfs ? {
         MOUNT_PATH: mountPath,
       } : undefined,
diff --git a/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment-cloudfront.expected.json b/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment-cloudfront.expected.json
index bd5c7309210e3..ee73484606056 100644
--- a/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment-cloudfront.expected.json
+++ b/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment-cloudfront.expected.json
@@ -343,7 +343,7 @@
             "Ref": "DeployWithInvalidationAwsCliLayerDEDD5787"
           }
         ],
-        "Runtime": "python3.6",
+        "Runtime": "python3.7",
         "Timeout": 900
       },
       "DependsOn": [
diff --git a/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment.expected.json b/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment.expected.json
index 8b247a49a4428..28a59330cb59b 100644
--- a/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment.expected.json
+++ b/packages/@aws-cdk/aws-s3-deployment/test/integ.bucket-deployment.expected.json
@@ -352,7 +352,7 @@
             "Ref": "DeployMeAwsCliLayer5F9219E9"
           }
         ],
-        "Runtime": "python3.6",
+        "Runtime": "python3.7",
         "Timeout": 900
       },
       "DependsOn": [
@@ -1495,7 +1495,7 @@
             "Ref": "DeployMeWithEfsStorageAwsCliLayer1619A3EE"
           }
         ],
-        "Runtime": "python3.6",
+        "Runtime": "python3.7",
         "Timeout": 900,
         "VpcConfig": {
           "SecurityGroupIds": [