diff --git a/Foundation/include/Poco/FIFOBuffer.h b/Foundation/include/Poco/FIFOBuffer.h
index 669a7dcbf..50ef408a7 100644
--- a/Foundation/include/Poco/FIFOBuffer.h
+++ b/Foundation/include/Poco/FIFOBuffer.h
@@ -325,7 +325,7 @@ public:
 		if (!isWritable())
 			throw Poco::InvalidAccessException("Buffer not writable.");
 
-		std::memcpy(&_buffer[_used], ptr, length * sizeof(T));
+		std::memcpy(begin() + _used, ptr, length * sizeof(T));
 		std::size_t usedBefore = _used;
 		_used += length;
 		if (_notify) notify(usedBefore);