-#define SCM_IS_WHVEC(X) (SCM_BITS (SCM_VELTS(X)[-1]) == 1)
-#define SCM_IS_WHVEC_V(X) (SCM_BITS (SCM_VELTS(X)[-1]) == 2)
-#define SCM_IS_WHVEC_B(X) (SCM_BITS (SCM_VELTS(X)[-1]) == 3)
+#define SCM_IS_WHVEC(X) (SCM_UNPACK (SCM_VELTS(X)[-1]) == 1)
+#define SCM_IS_WHVEC_V(X) (SCM_UNPACK (SCM_VELTS(X)[-1]) == 2)
+#define SCM_IS_WHVEC_B(X) (SCM_UNPACK (SCM_VELTS(X)[-1]) == 3)