diff --git a/lib/HttpServer/HttpCommTask.cpp b/lib/HttpServer/HttpCommTask.cpp
index b0b632c..1f79fb7 100644
--- a/lib/HttpServer/HttpCommTask.cpp
+++ b/lib/HttpServer/HttpCommTask.cpp
@@ -75,6 +75,8 @@ namespace triagens {
       bool handleRequest = false;
 
       if (! readRequestBody) {
+        MUTEX_LOCKER(readBufferLock);
+
         const char * ptr = readBuffer->c_str() + readPosition;
         const char * end = readBuffer->end() - 3;
 
@@ -197,7 +199,10 @@ namespace triagens {
 
       // we have to delete request in here or pass it to a handler, which will delete it
       if (handleRequest) {
-        readBuffer->erase_front(bodyPosition + bodyLength);
+        {
+          MUTEX_LOCKER(readBufferLock);
+          readBuffer->erase_front(bodyPosition + bodyLength);
+        }
 
         requestPending = true;
 
diff --git a/lib/Scheduler/SocketTask.cpp b/lib/Scheduler/SocketTask.cpp
index 76cd344..c75fe8c 100644
--- a/lib/Scheduler/SocketTask.cpp
+++ b/lib/Scheduler/SocketTask.cpp
@@ -324,6 +324,7 @@ bool SocketTask::fillReadBuffer (bool& closed) {
   int nr = read(commSocket, tmpReadBuffer, READ_BLOCK_SIZE);
 
   if (nr > 0) {
+    MUTEX_LOCKER(readBufferLock);
     readBuffer->appendText(tmpReadBuffer, nr);
 
     return true;
diff --git a/lib/Scheduler/SocketTask.h b/lib/Scheduler/SocketTask.h
index a23e852..66964ce 100644
--- a/lib/Scheduler/SocketTask.h
+++ b/lib/Scheduler/SocketTask.h
@@ -221,6 +221,12 @@ namespace triagens {
 
         mutable basics::Mutex writeBufferLock;
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief lock on the read buffer
+////////////////////////////////////////////////////////////////////////////////
+
+        mutable basics::Mutex readBufferLock;
+
       private:
         TRI_tid_t tid;
         char * tmpReadBuffer;