diff --git a/src/app/script/properties_class.cpp b/src/app/script/properties_class.cpp
index 6b5d38bd0..a04aebb3c 100644
--- a/src/app/script/properties_class.cpp
+++ b/src/app/script/properties_class.cpp
@@ -89,7 +89,7 @@ int Properties_newindex(lua_State* L)
       break;
 
     case LUA_TSTRING:
-      properties[field] = lua_tostring(L, 3);
+      properties[field] = std::string(lua_tostring(L, 3));
       break;
 
     case LUA_TTABLE: