diff --git a/libwvdrmengine/cdm/core/include/cdm_engine.h b/libwvdrmengine/cdm/core/include/cdm_engine.h
index 86ab9892..f6c3afec 100644
--- a/libwvdrmengine/cdm/core/include/cdm_engine.h
+++ b/libwvdrmengine/cdm/core/include/cdm_engine.h
@@ -106,8 +106,8 @@ class CdmEngine : public TimerHandler {
   // Cancel all sessions
   bool CancelSessions();
   void CleanupProvisioningSession(const CdmSessionId& cdm_session_id);
-  void ComposeJsonRequest(const std::string& message,
-                          CdmProvisioningRequest* request);
+  void ComposeJsonRequestAsQueryString(const std::string& message,
+                                       CdmProvisioningRequest* request);
 
   bool ParseJsonResponse(const CdmProvisioningResponse& json_str,
                          const std::string& start_substr,
diff --git a/libwvdrmengine/cdm/core/src/cdm_engine.cpp b/libwvdrmengine/cdm/core/src/cdm_engine.cpp
index c90f4372..fe517a13 100644
--- a/libwvdrmengine/cdm/core/src/cdm_engine.cpp
+++ b/libwvdrmengine/cdm/core/src/cdm_engine.cpp
@@ -333,17 +333,20 @@ void CdmEngine::CleanupProvisioningSession(const CdmSessionId& cdm_session_id) {
 }
 
 /*
- * This function converts SignedProvisioningRequest into base64 format.
+ * This function converts SignedProvisioningRequest into base64 string.
  * It then wraps it in JSON format expected by the Apiary frontend.
  * Apiary requires the base64 encoding to replace '+' with minus '-',
  * and '/' with underscore '_'; opposite to stubby's.
  *
- * Returns the JSON formated string in *request.
+ * Returns the JSON formated string in *request. The JSON string will be
+ * appended as a query parameter, i.e. signedRequest=<base 64 encoded
+ * SignedProvisioningRequest>. All base64 '=' padding chars must be removed.
+ *
  * The JSON formated request takes the following format:
- * 
- * {'signedRequest':'base64 encoded message'}
+ *
+ * base64 encoded message
  */
-void CdmEngine::ComposeJsonRequest(
+void CdmEngine::ComposeJsonRequestAsQueryString(
     const std::string& message,
     CdmProvisioningRequest* request) {
 
@@ -351,11 +354,14 @@ void CdmEngine::ComposeJsonRequest(
   std::vector<uint8_t> message_vector(message.begin(), message.end());
   std::string message_b64 = Base64SafeEncode(message_vector);
 
-  request->assign("{'signedRequest':'");
-  request->append(message_b64);
-  request->append("'}");
-
-  LOGD("json request:\r\n%s", request->c_str());
+  // removes trailing '=' padding characters;
+  // the encoded string can have at most 2 '=' padding chars, so start
+  // searching at the end minus four characters
+  size_t found_pos = message_b64.find("=", message_b64.size() - 4);
+  if (std::string::npos != found_pos) {
+    message_b64.resize(found_pos);
+  }
+  request->assign(message_b64);
 }
 
 /*
@@ -467,7 +473,7 @@ CdmResponseType CdmEngine::GetProvisioningRequest(
   signed_provisioning_msg.SerializeToString(&serialized_request);
 
   // converts request into JSON string
-  ComposeJsonRequest(serialized_request, request);
+  ComposeJsonRequestAsQueryString(serialized_request, request);
 
   return NO_ERROR;
 }
diff --git a/libwvdrmengine/cdm/core/test/url_request.cpp b/libwvdrmengine/cdm/core/test/url_request.cpp
index 6d57f860..3512dbd3 100644
--- a/libwvdrmengine/cdm/core/test/url_request.cpp
+++ b/libwvdrmengine/cdm/core/test/url_request.cpp
@@ -103,27 +103,21 @@ bool UrlRequest::PostRequest(const std::string& data) {
   return true;
 }
 
-void UrlRequest::AppendData(const std::string& data) {
-  request_.append(data);
-  request_.append("\r\n");  // marks end of data
-}
-
-bool UrlRequest::PostCertRequest(const std::string& data) {
+bool UrlRequest::PostCertRequestInQueryString(const std::string& data) {
   request_.assign("POST /");
   request_.append(socket_.resource_path());
+  request_.append("&signedRequest=");
+  request_.append(data);
   request_.append(" HTTP/1.1\r\n");
   request_.append("User-Agent: Widevine CDM v1.0\r\n");
   request_.append("Host: ");
   request_.append(socket_.domain_name());
   request_.append("\r\nAccept: */*");
   request_.append("\r\nContent-Type: application/json");
-  request_.append("\r\nContent-Length: ");
-  request_.append(UintToString(data.size()));
+  request_.append("\r\nContent-Length: 0");
   request_.append("\r\n");  // empty line to terminate header
   request_.append("\r\n");  // terminates the request
 
-  AppendData(data);
-
   socket_.Write(request_.c_str(), request_.size());
   return true;
 }
diff --git a/libwvdrmengine/cdm/core/test/url_request.h b/libwvdrmengine/cdm/core/test/url_request.h
index 119264ca..0d9d4a1e 100644
--- a/libwvdrmengine/cdm/core/test/url_request.h
+++ b/libwvdrmengine/cdm/core/test/url_request.h
@@ -17,12 +17,11 @@ class UrlRequest {
   ~UrlRequest();
 
   void AppendChunkToUpload(const std::string& data);
-  void AppendData(const std::string& data);
   int  GetResponse(std::string& response);
   int  GetStatusCode(const std::string& response);
   bool is_connected() const { return is_connected_; }
   bool PostRequest(const std::string& data);
-  bool PostCertRequest(const std::string& data);
+  bool PostCertRequestInQueryString(const std::string& data);
 
  private:
   static const unsigned int kHttpBufferSize = 4096;
diff --git a/libwvdrmengine/cdm/test/request_license_test.cpp b/libwvdrmengine/cdm/test/request_license_test.cpp
index d28a7fda..73bc805d 100644
--- a/libwvdrmengine/cdm/test/request_license_test.cpp
+++ b/libwvdrmengine/cdm/test/request_license_test.cpp
@@ -115,14 +115,14 @@ class WvCdmRequestLicenseTest : public testing::Test {
 
   // posts a request and extracts the drm message from the response
   std::string GetCertRequestResponse(const std::string& server_url,
-                                    int expected_response) {
+                                     int expected_response) {
     UrlRequest url_request(server_url, g_port);
 
     if (!url_request.is_connected()) {
       return "";
     }
 
-    url_request.PostCertRequest(key_msg_);
+    url_request.PostCertRequestInQueryString(key_msg_);
     std::string response;
     int resp_bytes = url_request.GetResponse(response);
     if (resp_bytes) {