diff --git a/programs/games/21days/Tupfile.lua b/programs/games/21days/Tupfile.lua
index 9cf9c5b472..425b3c07e0 100755
--- a/programs/games/21days/Tupfile.lua
+++ b/programs/games/21days/Tupfile.lua
@@ -2,6 +2,6 @@ if tup.getconfig("NO_GCC") ~= "" then return end
 HELPERDIR = (tup.getconfig("HELPERDIR") == "") and "../.." or tup.getconfig("HELPERDIR")
 tup.include(HELPERDIR .. "/use_gcc.lua")
 tup.include(HELPERDIR .. "/use_menuetlibc.lua")
-CFLAGS = CFLAGS .. " -D _KOS32 "
+CFLAGS = CFLAGS .. " -Wno-write-strings -D _KOS32 "
 compile_gcc{"main.cpp", "game.cpp", "interface.cpp", "sys.cpp"}
 link_gcc("21days")