diff --git a/libdevcore/Exceptions.h b/libdevcore/Exceptions.h
index f0d77043a..bb39cc3c9 100644
--- a/libdevcore/Exceptions.h
+++ b/libdevcore/Exceptions.h
@@ -46,7 +46,7 @@ struct FileError: virtual Exception {};
 typedef boost::error_info<struct tag_invalidSymbol, char> errinfo_invalidSymbol;
 typedef boost::error_info<struct tag_address, std::string> errinfo_wrongAddress;
 typedef boost::error_info<struct tag_comment, std::string> errinfo_comment;
-typedef boost::error_info<struct tag_required, int> errinfo_required;
-typedef boost::error_info<struct tag_got, int> errinfo_got;
+typedef boost::error_info<struct tag_required, size_t> errinfo_required;
+typedef boost::error_info<struct tag_got, size_t> errinfo_got;
 typedef boost::tuple<errinfo_required, errinfo_got> RequirementError;
 }