diff --git a/src/lp/detail/field-decl.hpp b/src/lp/detail/field-decl.hpp
index 49e3c07..3461906 100644
--- a/src/lp/detail/field-decl.hpp
+++ b/src/lp/detail/field-decl.hpp
@@ -125,7 +125,7 @@
   decode(const Block& wire)
   {
     if (wire.type() != TlvType::value) {
-      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + std::to_string(wire.type())));
+      BOOST_THROW_EXCEPTION(ndn::tlv::Error("Unexpected TLV type " + to_string(wire.type())));
     }
 
     return DecodeHelper<TlvType, ValueType>::decode(wire);