diff --git a/src/jamidht/multiplexed_socket.cpp b/src/jamidht/multiplexed_socket.cpp
index c99f4319ae6a85c86229a6a12e98053ce2d4efd5..37b888c2b6b2625d4c19b0e526397fa35832eca1 100644
--- a/src/jamidht/multiplexed_socket.cpp
+++ b/src/jamidht/multiplexed_socket.cpp
@@ -330,7 +330,7 @@ MultiplexedSocket::Impl::handleChannelPacket(uint16_t channel, std::vector<uint8
         }
     } else if (pkt.size() != 0) {
         std::string p = std::string(pkt.begin(), pkt.end());
-        JAMI_WARN("Non existing channel: %u - %.*s - %lu", channel, p.c_str(), pkt.size());
+        JAMI_WARN("Non existing channel: %u - %.*s", channel, (int) pkt.size(), p.c_str());
     }
 }