diff --git a/include/amqpcpp/callbacks.h b/include/amqpcpp/callbacks.h
index 66fef0d..e1881f7 100644
--- a/include/amqpcpp/callbacks.h
+++ b/include/amqpcpp/callbacks.h
@@ -45,7 +45,8 @@ using DeleteCallback        =   std::function<void(uint32_t deletedmessages)>;
  *  When retrieving the size of a queue in some way
  */
 using EmptyCallback         =   std::function<void()>;
-using SizeCallback          =   std::function<void(uint64_t messagecount)>;
+using CountCallback         =   std::function<void(uint32_t messagecount)>;
+using SizeCallback          =   std::function<void(uint64_t messagesize)>;
 
 /**
  *  Starting and stopping a consumer
diff --git a/include/amqpcpp/deferredget.h b/include/amqpcpp/deferredget.h
index 78332be..5f5716f 100644
--- a/include/amqpcpp/deferredget.h
+++ b/include/amqpcpp/deferredget.h
@@ -38,9 +38,9 @@ private:
 
     /**
      *  Callback with the number of messages still in the queue
-     *  @var    SizeCallback
+     *  @var    CountCallback
      */
-    SizeCallback _countCallback;
+    CountCallback _countCallback;
 
     /**
      *  Report success for a get operation
@@ -149,7 +149,7 @@ public:
      *  Register a function to be called when queue size information is known
      *  @param  callback    the callback to execute
      */
-    DeferredGet &onCount(const SizeCallback &callback)
+    DeferredGet &onCount(const CountCallback &callback)
     {
         // store callback
         _countCallback = callback;