diff --git a/clients/client-s3/src/S3Client.ts b/clients/client-s3/src/S3Client.ts
index 40cfea69a470..f3283b5a3217 100644
--- a/clients/client-s3/src/S3Client.ts
+++ b/clients/client-s3/src/S3Client.ts
@@ -1,5 +1,10 @@
 // smithy-typescript generated code
 import { getAddExpectContinuePlugin } from "@aws-sdk/middleware-expect-continue";
+import {
+  FlexibleChecksumsInputConfig,
+  FlexibleChecksumsResolvedConfig,
+  resolveFlexibleChecksumsConfig,
+} from "@aws-sdk/middleware-flexible-checksums";
 import {
   getHostHeaderPlugin,
   HostHeaderInputConfig,
@@ -729,6 +734,7 @@ export interface ClientDefaults extends Partial<__SmithyConfiguration<__HttpHand
 export type S3ClientConfigType = Partial<__SmithyConfiguration<__HttpHandlerOptions>> &
   ClientDefaults &
   UserAgentInputConfig &
+  FlexibleChecksumsInputConfig &
   RetryInputConfig &
   RegionInputConfig &
   HostHeaderInputConfig &
@@ -751,6 +757,7 @@ export type S3ClientResolvedConfigType = __SmithyResolvedConfiguration<__HttpHan
   Required<ClientDefaults> &
   RuntimeExtensionsConfig &
   UserAgentResolvedConfig &
+  FlexibleChecksumsResolvedConfig &
   RetryResolvedConfig &
   RegionResolvedConfig &
   HostHeaderResolvedConfig &
@@ -785,16 +792,17 @@ export class S3Client extends __Client<
     const _config_0 = __getRuntimeConfig(configuration || {});
     const _config_1 = resolveClientEndpointParameters(_config_0);
     const _config_2 = resolveUserAgentConfig(_config_1);
-    const _config_3 = resolveRetryConfig(_config_2);
-    const _config_4 = resolveRegionConfig(_config_3);
-    const _config_5 = resolveHostHeaderConfig(_config_4);
-    const _config_6 = resolveEndpointConfig(_config_5);
-    const _config_7 = resolveEventStreamSerdeConfig(_config_6);
-    const _config_8 = resolveHttpAuthSchemeConfig(_config_7);
-    const _config_9 = resolveS3Config(_config_8, { session: [() => this, CreateSessionCommand] });
-    const _config_10 = resolveRuntimeExtensions(_config_9, configuration?.extensions || []);
-    super(_config_10);
-    this.config = _config_10;
+    const _config_3 = resolveFlexibleChecksumsConfig(_config_2);
+    const _config_4 = resolveRetryConfig(_config_3);
+    const _config_5 = resolveRegionConfig(_config_4);
+    const _config_6 = resolveHostHeaderConfig(_config_5);
+    const _config_7 = resolveEndpointConfig(_config_6);
+    const _config_8 = resolveEventStreamSerdeConfig(_config_7);
+    const _config_9 = resolveHttpAuthSchemeConfig(_config_8);
+    const _config_10 = resolveS3Config(_config_9, { session: [() => this, CreateSessionCommand] });
+    const _config_11 = resolveRuntimeExtensions(_config_10, configuration?.extensions || []);
+    super(_config_11);
+    this.config = _config_11;
     this.middlewareStack.use(getUserAgentPlugin(this.config));
     this.middlewareStack.use(getRetryPlugin(this.config));
     this.middlewareStack.use(getContentLengthPlugin(this.config));
diff --git a/clients/client-s3/src/runtimeConfig.browser.ts b/clients/client-s3/src/runtimeConfig.browser.ts
index 7651945d8c1d..b0399198fa04 100644
--- a/clients/client-s3/src/runtimeConfig.browser.ts
+++ b/clients/client-s3/src/runtimeConfig.browser.ts
@@ -4,6 +4,10 @@ import packageInfo from "../package.json"; // eslint-disable-line
 
 import { Sha1 } from "@aws-crypto/sha1-browser";
 import { Sha256 } from "@aws-crypto/sha256-browser";
+import {
+  DEFAULT_REQUEST_CHECKSUM_CALCULATION,
+  DEFAULT_RESPONSE_CHECKSUM_VALIDATION,
+} from "@aws-sdk/middleware-flexible-checksums";
 import { defaultUserAgent } from "@aws-sdk/util-user-agent-browser";
 import { DEFAULT_USE_DUALSTACK_ENDPOINT, DEFAULT_USE_FIPS_ENDPOINT } from "@smithy/config-resolver";
 import { eventStreamSerdeProvider } from "@smithy/eventstream-serde-browser";
@@ -40,7 +44,9 @@ export const getRuntimeConfig = (config: S3ClientConfig) => {
     maxAttempts: config?.maxAttempts ?? DEFAULT_MAX_ATTEMPTS,
     md5: config?.md5 ?? Md5,
     region: config?.region ?? invalidProvider("Region is missing"),
+    requestChecksumCalculation: config?.requestChecksumCalculation ?? DEFAULT_REQUEST_CHECKSUM_CALCULATION,
     requestHandler: RequestHandler.create(config?.requestHandler ?? defaultConfigProvider),
+    responseChecksumValidation: config?.responseChecksumValidation ?? DEFAULT_RESPONSE_CHECKSUM_VALIDATION,
     retryMode: config?.retryMode ?? (async () => (await defaultConfigProvider()).retryMode || DEFAULT_RETRY_MODE),
     sha1: config?.sha1 ?? Sha1,
     sha256: config?.sha256 ?? Sha256,
diff --git a/clients/client-s3/src/runtimeConfig.ts b/clients/client-s3/src/runtimeConfig.ts
index 89e08626ab8f..a57fdb6773e0 100644
--- a/clients/client-s3/src/runtimeConfig.ts
+++ b/clients/client-s3/src/runtimeConfig.ts
@@ -5,6 +5,10 @@ import packageInfo from "../package.json"; // eslint-disable-line
 import { NODE_SIGV4A_CONFIG_OPTIONS, emitWarningIfUnsupportedVersion as awsCheckVersion } from "@aws-sdk/core";
 import { defaultProvider as credentialDefaultProvider } from "@aws-sdk/credential-provider-node";
 import { NODE_USE_ARN_REGION_CONFIG_OPTIONS } from "@aws-sdk/middleware-bucket-endpoint";
+import {
+  NODE_REQUEST_CHECKSUM_CALCULATION_CONFIG_OPTIONS,
+  NODE_RESPONSE_CHECKSUM_VALIDATION_CONFIG_OPTIONS,
+} from "@aws-sdk/middleware-flexible-checksums";
 import { NODE_DISABLE_S3_EXPRESS_SESSION_AUTH_OPTIONS } from "@aws-sdk/middleware-sdk-s3";
 import { ChecksumConstructor as __ChecksumConstructor, HashConstructor as __HashConstructor } from "@aws-sdk/types";
 import { defaultUserAgent } from "@aws-sdk/util-user-agent-node";
@@ -53,7 +57,11 @@ export const getRuntimeConfig = (config: S3ClientConfig) => {
     maxAttempts: config?.maxAttempts ?? loadNodeConfig(NODE_MAX_ATTEMPT_CONFIG_OPTIONS),
     md5: config?.md5 ?? Hash.bind(null, "md5"),
     region: config?.region ?? loadNodeConfig(NODE_REGION_CONFIG_OPTIONS, NODE_REGION_CONFIG_FILE_OPTIONS),
+    requestChecksumCalculation:
+      config?.requestChecksumCalculation ?? loadNodeConfig(NODE_REQUEST_CHECKSUM_CALCULATION_CONFIG_OPTIONS),
     requestHandler: RequestHandler.create(config?.requestHandler ?? defaultConfigProvider),
+    responseChecksumValidation:
+      config?.responseChecksumValidation ?? loadNodeConfig(NODE_RESPONSE_CHECKSUM_VALIDATION_CONFIG_OPTIONS),
     retryMode:
       config?.retryMode ??
       loadNodeConfig({