Index: source/lobby/scripting/JSInterface_Lobby.cpp
===================================================================
--- source/lobby/scripting/JSInterface_Lobby.cpp
+++ source/lobby/scripting/JSInterface_Lobby.cpp
@@ -516,8 +516,11 @@
 	crypto_hash_sha256_state state;
 	crypto_hash_sha256_init(&state);
 
+	std::string username_canonical = username;
+	std::for_each(username_canonical.begin(), username_canonical.end(), [](char & c){ c = ::tolower(c); });
+
 	crypto_hash_sha256_update(&state, salt_base, sizeof(salt_base));
-	crypto_hash_sha256_update(&state, (unsigned char*)username.c_str(), username.length());
+	crypto_hash_sha256_update(&state, (unsigned char*)username_canonical.c_str(), username_canonical.length());
 
 	crypto_hash_sha256_final(&state, salt_buffer);