diff --git a/src/HttpAuthenticationMiddleware.php b/src/HttpAuthenticationMiddleware.php
index 96a4fec..c385fb8 100644
--- a/src/HttpAuthenticationMiddleware.php
+++ b/src/HttpAuthenticationMiddleware.php
@@ -11,11 +11,24 @@ class HttpAuthenticationMiddleware
      */
     private $httpAuthenticationCredentials;
 
+    /**
+     * @var bool
+     */
+    private $isSingleUse = false;
+
     public function __construct()
     {
         $this->httpAuthenticationCredentials = new HttpAuthenticationCredentials();
     }
 
+    /**
+     * @param $isSingleUse
+     */
+    public function setIsSingleUse($isSingleUse)
+    {
+        $this->isSingleUse = $isSingleUse;
+    }
+
     /**
      * @param HttpAuthenticationCredentials $httpAuthenticationCredentials
      */
@@ -34,6 +47,11 @@ public function __invoke(callable $handler)
         return function (RequestInterface $request, array $options) use (&$handler) {
             $httpAuthenticationHeader = new HttpAuthenticationHeader($this->httpAuthenticationCredentials);
 
+            if ($this->isSingleUse) {
+                $this->httpAuthenticationCredentials = new HttpAuthenticationCredentials();
+                $this->isSingleUse = false;
+            }
+
             if (!$httpAuthenticationHeader->isValidForRequest($request)) {
                 return $handler($request, $options);
             }
diff --git a/tests/HttpAuthenticationMiddlewareTest.php b/tests/HttpAuthenticationMiddlewareTest.php
index 7a2efe9..2edc324 100644
--- a/tests/HttpAuthenticationMiddlewareTest.php
+++ b/tests/HttpAuthenticationMiddlewareTest.php
@@ -2,6 +2,7 @@
 
 namespace webignition\Guzzle\Middleware\HttpAuthentication\Tests;
 
+use Mockery\MockInterface;
 use Psr\Http\Message\RequestInterface;
 use webignition\Guzzle\Middleware\HttpAuthentication\HttpAuthenticationCredentials;
 use webignition\Guzzle\Middleware\HttpAuthentication\HttpAuthenticationHeader;
@@ -41,12 +42,7 @@ function ($returnedRequest, $returnedOptions) use ($request, $options) {
 
     public function testInvokeCredentialsInvalidForRequest()
     {
-        $request = \Mockery::mock(RequestInterface::class);
-
-        $request
-            ->shouldReceive('getHeaderLine')
-            ->with('host')
-            ->andReturn('example.com');
+        $request = $this->createOriginalRequest();
         $options = [];
 
         $credentials = new HttpAuthenticationCredentials('username', 'password', 'example.org');
@@ -62,34 +58,89 @@ function ($returnedRequest, $returnedOptions) use ($request, $options) {
         $returnedFunction($request, $options);
     }
 
-    public function testInvokeCredentialsValidForRequest()
+    public function testInvokeValidCredentialsAppliedToAllRequests()
     {
-        $modifiedRequest = \Mockery::mock(RequestInterface::class);
-
-        $request = \Mockery::mock(RequestInterface::class);
+        $credentials = new HttpAuthenticationCredentials('username', 'password', 'example.com');
+        $this->httpAuthenticationMiddleware->setHttpAuthenticationCredentials($credentials);
 
-        $request
-            ->shouldReceive('getHeaderLine')
-            ->with('host')
-            ->andReturn('example.com');
+        $requestCount = 3;
 
-        $request
+        $modifiedRequest = \Mockery::mock(RequestInterface::class);
+        $originalRequest = $this->createOriginalRequest();
+        $originalRequest
             ->shouldReceive('withHeader')
             ->with(HttpAuthenticationHeader::NAME, 'Basic dXNlcm5hbWU6cGFzc3dvcmQ=')
             ->andReturn($modifiedRequest);
 
-        $options = [];
+        for ($requestIndex = 0; $requestIndex < $requestCount; $requestIndex++) {
+            $options = [];
+
+            $returnedFunction = $this->httpAuthenticationMiddleware->__invoke(
+                function ($returnedRequest, $returnedOptions) use ($modifiedRequest, $options) {
+                    $this->assertEquals($modifiedRequest, $returnedRequest);
+                    $this->assertEquals($options, $returnedOptions);
+                }
+            );
 
+            $returnedFunction($originalRequest, $options);
+        }
+    }
+
+    public function testInvokeValidCredentialsAppliedToFirstRequestOnly()
+    {
         $credentials = new HttpAuthenticationCredentials('username', 'password', 'example.com');
         $this->httpAuthenticationMiddleware->setHttpAuthenticationCredentials($credentials);
+        $this->httpAuthenticationMiddleware->setIsSingleUse(true);
 
-        $returnedFunction = $this->httpAuthenticationMiddleware->__invoke(
-            function ($returnedRequest, $returnedOptions) use ($modifiedRequest, $options) {
-                $this->assertEquals($modifiedRequest, $returnedRequest);
-                $this->assertEquals($options, $returnedOptions);
+        $requestCount = 3;
+        $modifiedRequest = \Mockery::mock(RequestInterface::class);
+        $originalRequest = $this->createOriginalRequest();
+
+        for ($requestIndex = 0; $requestIndex < $requestCount; $requestIndex++) {
+            if ($requestIndex === 0) {
+                $originalRequest
+                    ->shouldReceive('withHeader')
+                    ->with(HttpAuthenticationHeader::NAME, 'Basic dXNlcm5hbWU6cGFzc3dvcmQ=')
+                    ->andReturn($modifiedRequest);
             }
-        );
 
-        $returnedFunction($request, $options);
+            $options = [];
+
+            $returnedFunction = $this->httpAuthenticationMiddleware->__invoke(
+                function (
+                    $returnedRequest,
+                    $returnedOptions
+                ) use (
+                    $originalRequest,
+                    $modifiedRequest,
+                    $options,
+                    $requestIndex
+                ) {
+                    if ($requestIndex === 0) {
+                        $this->assertEquals($modifiedRequest, $returnedRequest);
+                    } else {
+                        $this->assertEquals($originalRequest, $returnedRequest);
+                    }
+
+                    $this->assertEquals($options, $returnedOptions);
+                }
+            );
+
+            $returnedFunction($originalRequest, $options);
+        }
+    }
+
+    /**
+     * @return MockInterface|RequestInterface
+     */
+    private function createOriginalRequest()
+    {
+        $request = \Mockery::mock(RequestInterface::class);
+        $request
+            ->shouldReceive('getHeaderLine')
+            ->with('host')
+            ->andReturn('example.com');
+
+        return $request;
     }
 }