diff --git a/code/nel/src/gui/lua_object.cpp b/code/nel/src/gui/lua_object.cpp
index dc7abff52..57581d6ec 100644
--- a/code/nel/src/gui/lua_object.cpp
+++ b/code/nel/src/gui/lua_object.cpp
@@ -422,7 +422,7 @@ namespace NLGUI
 	{
 		nlassert(key);
 		nlassert(isValid());
-		if (!isTable()) throw ELuaNotATable(NLMISC::toString("Trying to set a value '%d" NL_I64 "' at key %s on object '%s' of type %s (not a table).", value, key, getId().c_str(), getTypename()));
+		if (!isTable()) throw ELuaNotATable(NLMISC::toString("Trying to set a value '%" NL_I64 "d' at key %s on object '%s' of type %s (not a table).", value, key, getId().c_str(), getTypename()));
 		CLuaStackChecker lsc(_LuaState);
 		push();
 		_LuaState->push(key);