diff --git a/rndx.lua b/rndx.lua
index 4b1615a..ecd4f6a 100644
--- a/rndx.lua
+++ b/rndx.lua
@@ -225,6 +225,7 @@ RNDX.SHAPE_IOS = SHAPE_IOS
 RNDX.BLUR = BLUR
 
 function RNDX.SetFlag(flags, flag, bool)
+    flag = RNDX[flag] or flag
     if tobool(bool) then
         return bit.bor(flags, flag)
     else