-# define TESTBIT(t, b) (t[(b) >> 3] & (1 << ((b) & 7)))
-# define SETBIT(t, b) (t[(b) >> 3] |= (1 << ((b) & 7)))
-# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(1 << ((b) & 7))))
+#define ONE ((size_t)1)
+
+# define TESTBIT(t, b) (t[(b) >> 3] & (ONE << ((b) & 7)))
+# define SETBIT(t, b) (t[(b) >> 3] |= (ONE << ((b) & 7)))
+# define CLEARBIT(t, b) (t[(b) >> 3] &= (0xFF & ~(ONE << ((b) & 7))))