diff --git a/src/lua-lxc/core.c b/src/lua-lxc/core.c
index 630a3e4..34180a7 100644
--- a/src/lua-lxc/core.c
+++ b/src/lua-lxc/core.c
@@ -39,8 +39,10 @@
 #endif
 
 #if LUA_VERSION_NUM >= 503
+#ifndef luaL_checkunsigned
 #define luaL_checkunsigned(L,n) ((lua_Unsigned)luaL_checkinteger(L,n))
 #endif
+#endif
 
 #ifdef NO_CHECK_UDATA
 #define checkudata(L,i,tname)	lua_touserdata(L, i)