diff --git a/ext/mbstring/mbstring.h b/ext/mbstring/mbstring.h
index 8e4bd2b9112..197e160ecc5 100644
--- a/ext/mbstring/mbstring.h
+++ b/ext/mbstring/mbstring.h
@@ -143,6 +143,9 @@ MBSTRING_API int php_mb_encoding_detector_ex(const char *arg_string, int arg_len
 
 MBSTRING_API int php_mb_encoding_converter_ex(char **str, int *len, const char *encoding_to, 
 											  const char *encoding_from TSRMLS_DC);
+MBSTRING_API int php_mb_gpc_encoding_converter(char **str, int *len, const char *encoding_to, const char *encoding_from TSRMLS_DC);
+
+MBSTRING_API int php_mb_gpc_encoding_detector(const char *arg_string, int arg_length, char *arg_list TSRMLS_DC);
 
 ZEND_BEGIN_MODULE_GLOBALS(mbstring)
 	enum mbfl_no_language language;