diff --git a/modules/core/include/opencv2/core/operations.hpp b/modules/core/include/opencv2/core/operations.hpp
index f8aeddfb1..1760d8776 100644
--- a/modules/core/include/opencv2/core/operations.hpp
+++ b/modules/core/include/opencv2/core/operations.hpp
@@ -393,7 +393,9 @@ template<typename _Tp> static inline _Tp randu()
   return (_Tp)theRNG();
 }
 
+///////////////////////////////// Formatted string generation /////////////////////////////////
 
+CV_EXPORTS String format( const char* fmt, ... );
 
 ///////////////////////////////// Formatted output of cv::Mat /////////////////////////////////