diff --git a/.changes/nextrelease/configured-signature-version.json b/.changes/nextrelease/configured-signature-version.json
new file mode 100644
index 0000000000..dd4761264e
--- /dev/null
+++ b/.changes/nextrelease/configured-signature-version.json
@@ -0,0 +1,7 @@
+[
+  {
+    "type": "bugfix",
+    "category": "",
+    "description": "Fixes issue with manually configured signature versions."
+  }
+]
\ No newline at end of file
diff --git a/src/AwsClient.php b/src/AwsClient.php
index 33e270017d..3f2b03699e 100644
--- a/src/AwsClient.php
+++ b/src/AwsClient.php
@@ -233,7 +233,7 @@ public function __construct(array $args)
         $this->defaultRequestOptions = $config['http'];
         $this->endpointProvider = $config['endpoint_provider'];
         $this->serializer = $config['serializer'];
-        $this->addSignatureMiddleware();
+        $this->addSignatureMiddleware($args);
         $this->addInvocationId();
         $this->addEndpointParameterMiddleware($args);
         $this->addEndpointDiscoveryMiddleware($config, $args);
@@ -403,7 +403,7 @@ private function addEndpointDiscoveryMiddleware($config, $args)
         }
     }
 
-    private function addSignatureMiddleware()
+    private function addSignatureMiddleware(array $args)
     {
         $api = $this->getApi();
         $provider = $this->signatureProvider;
@@ -411,9 +411,17 @@ private function addSignatureMiddleware()
         $name = $this->config['signing_name'];
         $region = $this->config['signing_region'];
 
+        if (isset($args['signature_version'])
+         || isset($this->config['configured_signature_version'])
+        ) {
+            $configuredSignatureVersion = true;
+        } else {
+            $configuredSignatureVersion = false;
+        }
+
         $resolver = static function (
             CommandInterface $c
-        ) use ($api, $provider, $name, $region, $version) {
+        ) use ($api, $provider, $name, $region, $version, $configuredSignatureVersion) {
             if (!empty($c['@context']['signing_region'])) {
                 $region = $c['@context']['signing_region'];
             }
@@ -421,30 +429,33 @@ private function addSignatureMiddleware()
                 $name = $c['@context']['signing_service'];
             }
 
-            $authType = $api->getOperation($c->getName())['authtype'];
-            switch ($authType){
-                case 'none':
-                    $version = 'anonymous';
-                    break;
-                case 'v4-unsigned-body':
-                    $version = 'v4-unsigned-body';
-                    break;
-                case 'bearer':
-                    $version = 'bearer';
-                    break;
-            }
-            if (isset($c['@context']['signature_version'])) {
-                if ($c['@context']['signature_version'] == 'v4a') {
-                    $version = 'v4a';
+            if (!$configuredSignatureVersion) {
+                $authType = $api->getOperation($c->getName())['authtype'];
+                switch ($authType){
+                    case 'none':
+                        $version = 'anonymous';
+                        break;
+                    case 'v4-unsigned-body':
+                        $version = 'v4-unsigned-body';
+                        break;
+                    case 'bearer':
+                        $version = 'bearer';
+                        break;
+                }
+                if (isset($c['@context']['signature_version'])) {
+                    if ($c['@context']['signature_version'] == 'v4a') {
+                        $version = 'v4a';
+                    }
+                }
+                if (!empty($endpointAuthSchemes = $c->getAuthSchemes())) {
+                    $version = $endpointAuthSchemes['version'];
+                    $name = isset($endpointAuthSchemes['name']) ?
+                        $endpointAuthSchemes['name'] : $name;
+                    $region = isset($endpointAuthSchemes['region']) ?
+                        $endpointAuthSchemes['region'] : $region;
                 }
             }
-            if (!empty($endpointAuthSchemes = $c->getAuthSchemes())) {
-                $version = $endpointAuthSchemes['version'];
-                $name = isset($endpointAuthSchemes['name']) ?
-                    $endpointAuthSchemes['name'] : $name;
-                $region = isset($endpointAuthSchemes['region']) ?
-                    $endpointAuthSchemes['region'] : $region;
-            }
+
             return SignatureProvider::resolve($provider, $version, $name, $region);
         };
         $this->handlerList->appendSign(
diff --git a/src/ClientResolver.php b/src/ClientResolver.php
index fd9427dc26..e0b650fb24 100644
--- a/src/ClientResolver.php
+++ b/src/ClientResolver.php
@@ -608,6 +608,7 @@ public static function _apply_credentials($value, array &$args)
                 new Credentials('', '')
             );
             $args['config']['signature_version'] = 'anonymous';
+            $args['config']['configured_signature_version'] = true;
         } elseif ($value instanceof CacheInterface) {
             $args['credentials'] = CredentialProvider::defaultProvider($args);
         } else {
diff --git a/tests/AwsClientTest.php b/tests/AwsClientTest.php
index bc354f83ba..a9aabeb843 100644
--- a/tests/AwsClientTest.php
+++ b/tests/AwsClientTest.php
@@ -10,6 +10,7 @@
 use Aws\Endpoint\UseFipsEndpoint\Configuration as FipsConfiguration;
 use Aws\Endpoint\UseDualStackEndpoint\Configuration as DualStackConfiguration;
 use Aws\EndpointV2\EndpointProviderV2;
+use Aws\Middleware;
 use Aws\ResultPaginator;
 use Aws\S3\Exception\S3Exception;
 use Aws\Ses\SesClient;
@@ -670,6 +671,61 @@ public function configuredEndpointUrlProvider()
         ];
     }
 
+    public function testAppliesConfiguredSignatureVersionViaFalseCredentials()
+    {
+        $client = new S3Client([
+            'region' => 'us-west-2',
+            'handler' => new MockHandler([new Result([])]),
+            'credentials' => false
+        ]);
+
+        $this->assertTrue($client->getConfig('configured_signature_version'));
+
+        $list = $client->getHandlerList();
+        $list->appendSign(Middleware::tap(function($cmd, $req) {
+            foreach (['Authorization', 'X-Amz-Date'] as $signatureHeader) {
+                $this->assertFalse($req->hasHeader($signatureHeader));
+            }
+        }));
+
+        $client->putObject([
+            'Bucket' => 'foo',
+            'Key' => 'bar',
+            'Body' => 'test'
+        ]);
+    }
+
+    public function testAppliesConfiguredSignatureVersionViaClientConfig() {
+        $client = $this->createClient(
+            [
+                'metadata' => [
+                    'signatureVersion' => 'v4',
+                ],
+                'operations' => [
+                    'Foo' => [
+                        'http' => ['method' => 'POST'],
+                        'authtype' => 'none',
+                    ],
+                ],
+            ],
+            [
+                'handler' => function (
+                    CommandInterface $command,
+                    RequestInterface $request
+                ) {
+                    foreach (['Authorization', 'X-Amz-Date'] as $signatureHeader) {
+                        $this->assertTrue($request->hasHeader($signatureHeader));
+                    }
+
+                    return new Result;
+                },
+                'signature_version' => 'v4'
+            ]
+        );
+
+        $client->foo();
+    }
+
     private function createHttpsEndpointClient(array $service = [], array $config = [])
     {
         $apiProvider = function () use ($service) {