Sparse array limit testing: reduce the range limit for the number of bits
in a sparse array pointer block.
# else
# define OPENSSL_SA_BLOCK_BITS 12
# endif
-#elif OPENSSL_SA_BLOCK_BITS < 2 || OPENSSL_SA_BLOCK_BITS > BN_BITS2
+#elif OPENSSL_SA_BLOCK_BITS < 2 || OPENSSL_SA_BLOCK_BITS > (BN_BITS2 - 1)
# error OPENSSL_SA_BLOCK_BITS is out of range
#endif
