diff --git a/.changes/next-release/feature-ChainableTemporaryCredentials-5b0ffa87.json b/.changes/next-release/feature-ChainableTemporaryCredentials-5b0ffa87.json
new file mode 100644
index 0000000000..5f5e00e8bb
--- /dev/null
+++ b/.changes/next-release/feature-ChainableTemporaryCredentials-5b0ffa87.json
@@ -0,0 +1,5 @@
+{
+  "type": "feature",
+  "category": "ChainableTemporaryCredentials",
+  "description": "Support for specifying STS client config when creating ChainableTemporaryCredentials to override endpoint or region."
+}
diff --git a/dist/aws-sdk-react-native.js b/dist/aws-sdk-react-native.js
index 3ee4fe0bda..35695a90bc 100644
--- a/dist/aws-sdk-react-native.js
+++ b/dist/aws-sdk-react-native.js
@@ -17825,10 +17825,14 @@ return /******/ (function(modules) { // webpackBootstrap
 	        this.tokenCodeFn = options.tokenCodeFn;
 	      }
 	    }
-	    this.service = new STS({
-	      params: params,
-	      credentials: options.masterCredentials || AWS.config.credentials
-	    });
+	    config = AWS.util.merge(
+	      {
+	        params: params,
+	        credentials: options.masterCredentials || AWS.config.credentials
+	      },
+	      options.stsConfig || {}
+	    );
+	    this.service = new STS(config);
 	  },
 
 	  /**
diff --git a/lib/credentials/chainable_temporary_credentials.d.ts b/lib/credentials/chainable_temporary_credentials.d.ts
index d71656d9af..5ef8520564 100644
--- a/lib/credentials/chainable_temporary_credentials.d.ts
+++ b/lib/credentials/chainable_temporary_credentials.d.ts
@@ -3,7 +3,7 @@ import {AWSError} from '../error';
 import STS = require('../../clients/sts');
 
 export class ChainableTemporaryCredentials extends Credentials {
-    constructor(options: ChainableTemporaryCredentials.ChainableTemporaryCredentialsOptions, masterCredentials?: Credentials);
+    constructor(options: ChainableTemporaryCredentials.ChainableTemporaryCredentialsOptions);
     /**
      * Creates a new temporary credentials object.
      */
@@ -24,6 +24,7 @@ declare namespace ChainableTemporaryCredentials {
     export type ChainableTemporaryCredentialsOptions = {
         params?: STS.Types.AssumeRoleRequest|STS.Types.GetSessionTokenRequest,
         masterCredentials?: Credentials,
+        stsConfig: STS.Types.ClientConfiguration,
         tokenCodeFn?: (serialNumber: string, callback: (err?: Error, token?: string) => void) => void
     }
 }
diff --git a/lib/credentials/chainable_temporary_credentials.js b/lib/credentials/chainable_temporary_credentials.js
index 7dc6e9daea..f286eac41a 100644
--- a/lib/credentials/chainable_temporary_credentials.js
+++ b/lib/credentials/chainable_temporary_credentials.js
@@ -119,10 +119,14 @@ AWS.ChainableTemporaryCredentials = AWS.util.inherit(AWS.Credentials, {
         this.tokenCodeFn = options.tokenCodeFn;
       }
     }
-    this.service = new STS({
-      params: params,
-      credentials: options.masterCredentials || AWS.config.credentials
-    });
+    config = AWS.util.merge(
+      {
+        params: params,
+        credentials: options.masterCredentials || AWS.config.credentials
+      },
+      options.stsConfig || {}
+    );
+    this.service = new STS(config);
   },
 
   /**
diff --git a/package.json b/package.json
index 453c8b2760..f08e2be1a3 100644
--- a/package.json
+++ b/package.json
@@ -143,4 +143,4 @@
     "helper-test": "mocha scripts/lib/test-helper.spec.js",
     "csm-functional-test": "mocha test/publisher/functional_test"
   }
-}
\ No newline at end of file
+}
diff --git a/test/credentials.spec.js b/test/credentials.spec.js
index 758c7c7af7..94d41f1a98 100644
--- a/test/credentials.spec.js
+++ b/test/credentials.spec.js
@@ -1609,6 +1609,12 @@
         });
         expect(creds).to.have.property('tokenCodeFn', null);
       });
+      it('should forward enpoint param to sts client', function() {
+        var creds = new AWS.ChainableTemporaryCredentials({
+          stsConfig: { endpoint: 'https://testendpoint' }
+        });
+        expect(creds.service.endpoint.hostname).to.equal('testendpoint');
+      });
     });
     describe('masterCredentials', function() {
       var origCreds, origProvider;