diff --git a/arangod/VocBase/vocbase.cpp b/arangod/VocBase/vocbase.cpp
index 9e8469dfee..07d91a88a0 100644
--- a/arangod/VocBase/vocbase.cpp
+++ b/arangod/VocBase/vocbase.cpp
@@ -205,7 +205,6 @@ static int WriteDropCollectionMarker (TRI_vocbase_t* vocbase,
 static bool UnregisterCollection (TRI_vocbase_t* vocbase,
                                   TRI_vocbase_col_t* collection) {
   TRI_ASSERT(collection != nullptr);
-  TRI_ASSERT(collection->_name != nullptr);
 
   TRI_WRITE_LOCK_COLLECTIONS_VOCBASE(vocbase);
 
diff --git a/lib/HttpServer/AsyncJobManager.cpp b/lib/HttpServer/AsyncJobManager.cpp
index b7d674e6a8..deac33c91a 100644
--- a/lib/HttpServer/AsyncJobManager.cpp
+++ b/lib/HttpServer/AsyncJobManager.cpp
@@ -346,8 +346,8 @@ void AsyncJobManager::initAsyncJob (HttpServerJob* job, uint64_t* jobId) {
 
   TRI_ASSERT(job != nullptr);
 
-  *jobId = (AsyncJobResult::IdType) generate();
-  job->assignId((uint64_t) *jobId);
+  *jobId = generate();
+  job->assignId(*jobId);
 
   AsyncCallbackContext* ctx = nullptr;
 
diff --git a/lib/HttpServer/HttpHandler.cpp b/lib/HttpServer/HttpHandler.cpp
index ecc0335d36..4dd37e1ee5 100644
--- a/lib/HttpServer/HttpHandler.cpp
+++ b/lib/HttpServer/HttpHandler.cpp
@@ -143,9 +143,9 @@ Job* HttpHandler::createJob (HttpServer* server, bool isDetached) {
 ////////////////////////////////////////////////////////////////////////////////
 
 void HttpHandler::removePreviousResponse () {
-  if (_response != 0) {
+  if (_response != nullptr) {
     delete _response;
-    _response = 0;
+    _response = nullptr;
   }
 }
 
diff --git a/lib/HttpServer/HttpServer.cpp b/lib/HttpServer/HttpServer.cpp
index c1119ba610..e77c86c703 100644
--- a/lib/HttpServer/HttpServer.cpp
+++ b/lib/HttpServer/HttpServer.cpp
@@ -455,9 +455,7 @@ bool HttpServer::handleRequestAsync (HttpHandler* handler, uint64_t* jobId) {
   HttpServerJob* job = dynamic_cast<HttpServerJob*>(ajob);
 
   if (job == nullptr) {
-    if (ajob != nullptr) {
-      delete ajob;
-    }
+    delete ajob;
 
     RequestStatisticsAgentSetExecuteError(handler);
 
@@ -467,22 +465,26 @@ bool HttpServer::handleRequestAsync (HttpHandler* handler, uint64_t* jobId) {
     return false;
   }
 
-  if (jobId != 0) {
+  if (jobId != nullptr) {
     try {
       _jobManager->initAsyncJob(job, jobId);
     }
     catch (...) {
+      RequestStatisticsAgentSetExecuteError(handler);
       LOG_WARNING("unable to initialize job");
-              
+      delete job;
       delete handler;
       return false;
     }
   }
 
-  if (_dispatcher->addJob(job) != TRI_ERROR_NO_ERROR) {
+  int error = _dispatcher->addJob(job);
+  if (error != TRI_ERROR_NO_ERROR) {
     // could not add job to job queue
+    RequestStatisticsAgentSetExecuteError(handler);
+    LOG_WARNING("unable to add job to the job queue: %s", TRI_errno_string(error));
+    delete job;
     delete handler;
-
     return false;
   }
 
@@ -773,7 +775,7 @@ void HttpServer::registerHandler (HttpHandler* handler, HttpCommTask* task) {
   handler_task_job_t element;
   element._handler = handler;
   element._task = task;
-  element._job = 0;
+  element._job = nullptr;
 
   _handlers[handler] = element;
   _task2handler[task] = element;