diff --git a/src/_cffi_src/openssl/bignum.py b/src/_cffi_src/openssl/bignum.py
index 0f1f83c..eab4028 100644
--- a/src/_cffi_src/openssl/bignum.py
+++ b/src/_cffi_src/openssl/bignum.py
@@ -19,14 +19,12 @@
 #define BN_FLG_CONSTTIME ...
 
 void BN_set_flags(BIGNUM *, int);
-int BN_get_flags(const BIGNUM *, int);
 
 BIGNUM *BN_new(void);
 void BN_free(BIGNUM *);
 void BN_clear_free(BIGNUM *);
 
-int BN_rand(BIGNUM *, int, int, int);
-int BN_rand_range(BIGNUM *, BIGNUM *);
+int BN_rand_range(BIGNUM *, const BIGNUM *);
 
 BN_CTX *BN_CTX_new(void);
 void BN_CTX_free(BN_CTX *);
@@ -36,20 +34,17 @@
 void BN_CTX_end(BN_CTX *);
 
 BN_MONT_CTX *BN_MONT_CTX_new(void);
-int BN_MONT_CTX_set(BN_MONT_CTX *, BIGNUM *, BN_CTX *);
+int BN_MONT_CTX_set(BN_MONT_CTX *, const BIGNUM *, BN_CTX *);
 void BN_MONT_CTX_free(BN_MONT_CTX *);
 
-BIGNUM *BN_copy(BIGNUM *, const BIGNUM *);
 BIGNUM *BN_dup(const BIGNUM *);
 
 int BN_set_word(BIGNUM *, BN_ULONG);
-BN_ULONG BN_get_word(const BIGNUM *);
 
 const BIGNUM *BN_value_one(void);
 
 char *BN_bn2hex(const BIGNUM *);
 int BN_hex2bn(BIGNUM **, const char *);
-int BN_dec2bn(BIGNUM **, const char *);
 
 int BN_bn2bin(const BIGNUM *, unsigned char *);
 BIGNUM *BN_bin2bn(const unsigned char *, int, BIGNUM *);
@@ -59,9 +54,6 @@
 int BN_cmp(const BIGNUM *, const BIGNUM *);
 int BN_add(BIGNUM *, const BIGNUM *, const BIGNUM *);
 int BN_sub(BIGNUM *, const BIGNUM *, const BIGNUM *);
-int BN_mul(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
-int BN_sqr(BIGNUM *, const BIGNUM *, BN_CTX *);
-int BN_div(BIGNUM *, BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
 int BN_nnmod(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
 int BN_mod_add(BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
                BN_CTX *);
@@ -69,35 +61,17 @@
                BN_CTX *);
 int BN_mod_mul(BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
                BN_CTX *);
-int BN_mod_sqr(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
-int BN_exp(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
 int BN_mod_exp(BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
                BN_CTX *);
 int BN_mod_exp_mont(BIGNUM *, const BIGNUM *, const BIGNUM *, const BIGNUM *,
                     BN_CTX *, BN_MONT_CTX *);
 int BN_mod_exp_mont_consttime(BIGNUM *, const BIGNUM *, const BIGNUM *,
                               const BIGNUM *, BN_CTX *, BN_MONT_CTX *);
-int BN_gcd(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
 BIGNUM *BN_mod_inverse(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
 
-int BN_set_bit(BIGNUM *, int);
-int BN_clear_bit(BIGNUM *, int);
-
-int BN_is_bit_set(const BIGNUM *, int);
-
-int BN_mask_bits(BIGNUM *, int);
-
 int BN_num_bytes(const BIGNUM *);
 
-int BN_zero(BIGNUM *);
-int BN_one(BIGNUM *);
 int BN_mod(BIGNUM *, const BIGNUM *, const BIGNUM *, BN_CTX *);
-
-int BN_lshift(BIGNUM *, const BIGNUM *, int);
-int BN_lshift1(BIGNUM *, BIGNUM *);
-
-int BN_rshift(BIGNUM *, BIGNUM *, int);
-int BN_rshift1(BIGNUM *, BIGNUM *);
 """
 
 CUSTOMIZATIONS = """