--- src/core/CLucene/store/IndexOutput.h
+++ src/core/CLucene/store/IndexOutput.h
@@ -159,7 +159,7 @@
 	* @param b the bytes to write
 	* @param len the number of bytes to write
 	*/
-	virtual void flushBuffer(const uint8_t* b, const int32_t len) = 0;
+	virtual void flushBuffer(const uint8_t* /*b*/, const int32_t /*len*/) {}
 };
 
 CL_NS_END