diff --git a/src/challenge/challenge-pin.hpp b/src/challenge/challenge-pin.hpp
index 757870d..61e0fb6 100644
--- a/src/challenge/challenge-pin.hpp
+++ b/src/challenge/challenge-pin.hpp
@@ -60,7 +60,7 @@
 
   Block
   genChallengeRequestTLV(Status status, const std::string& challengeStatus,
-                         std::multimap<std::string, std::string>&& params) override;
+                         const std::multimap<std::string, std::string>& params) override;
 
   // challenge status
   static const std::string NEED_CODE;