diff --git a/src/Core/HttpClients/IntuitResponse.php b/src/Core/HttpClients/IntuitResponse.php
index 60a75451..72f20f9e 100644
--- a/src/Core/HttpClients/IntuitResponse.php
+++ b/src/Core/HttpClients/IntuitResponse.php
@@ -86,8 +86,9 @@ private function setResponseAsItIs($passedHeaders, $passedBody, $passedHttpRespo
           $this->headers = $passedHeaders;
           $this->body = $passedBody;
           $this->httpResponseCode = $passedHttpResponseCode;
-          $this->setContentType(CoreConstants::CONTENT_TYPE, $passedHeaders[CoreConstants::CONTENT_TYPE]);
-          $this->setIntuitTid(CoreConstants::INTUIT_TID, $passedHeaders[CoreConstants::INTUIT_TID]);
+          $passedHeaders = array_change_key_case($passedHeaders, CASE_LOWER);
+          $this->setContentType(CoreConstants::CONTENT_TYPE, $passedHeaders[strtolower(CoreConstants::CONTENT_TYPE)]);
+          $this->setIntuitTid(CoreConstants::INTUIT_TID, $passedHeaders[strtolower(CoreConstants::INTUIT_TID)]);
           $this->setFaultHandler($passedBody, $passedHttpResponseCode, $this->getIntuitTid());
       }else{
           throw new SdkException("Passed Headers, body, or status code is Null.");
diff --git a/src/Core/HttpClients/SyncRestHandler.php b/src/Core/HttpClients/SyncRestHandler.php
index e9e9a595..efaa8bd2 100644
--- a/src/Core/HttpClients/SyncRestHandler.php
+++ b/src/Core/HttpClients/SyncRestHandler.php
@@ -206,6 +206,7 @@ private function OAuth2APICall($baseURL, $queryParameters, $HttpMethod, $request
         $intuitResponse = $this->httpClientInterface->makeAPICall($requestUri, $HttpMethod, $httpHeaders,  $requestBody, null, true);
         $faultHandler = $intuitResponse->getFaultHandler();
         $this->LogAPIResponseToLog($intuitResponse->getBody(), $requestUri, $intuitResponse->getHeaders());
+
         //Based on the ducomentation, the fetch expected HTTP/1.1 20X or a redirect. If not, any 3xx, 4xx or 5xx will throw an OAuth Exception
         //for 3xx without direct, it will throw a 503 code and error saying: Invalid protected resource url, unable to generate signature base string
         if($faultHandler) {
@@ -267,8 +268,9 @@ private function setCommonHeadersForPHPSDK($AuthorizationHeader, $requestUri, $C
      * @param Array $httpHeaders  The headers for the request
      */
     public function LogAPIResponseToLog($body, $requestUri, $httpHeaders){
-      if(strcasecmp($httpHeaders[CoreConstants::CONTENT_TYPE], CoreConstants::CONTENTTYPE_APPLICATIONXML) == 0 ||
-          strcasecmp($httpHeaders[CoreConstants::CONTENT_TYPE], CoreConstants::CONTENTTYPE_APPLICATIONXML_WITH_CHARSET) == 0){
+      $httpHeaders = array_change_key_case($httpHeaders, CASE_LOWER);
+      if(strcasecmp($httpHeaders[strtolower(CoreConstants::CONTENT_TYPE)], CoreConstants::CONTENTTYPE_APPLICATIONXML) == 0 ||
+          strcasecmp($httpHeaders[strtolower(CoreConstants::CONTENT_TYPE)], CoreConstants::CONTENTTYPE_APPLICATIONXML_WITH_CHARSET) == 0){
              $body = $this->parseStringToDom($body);
       }