diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h
index e591d4ca0..f1719a587 100644
--- a/crypto/bn/bn.h
+++ b/crypto/bn/bn.h
@@ -408,8 +408,8 @@ BIGNUM *BN_CTX_get(BN_CTX *ctx);
 void	BN_CTX_end(BN_CTX *ctx);
 int     BN_rand(BIGNUM *rnd, int bits, int top,int bottom);
 int     BN_pseudo_rand(BIGNUM *rnd, int bits, int top,int bottom);
-int	BN_rand_range(BIGNUM *rnd, BIGNUM *range);
-int	BN_pseudo_rand_range(BIGNUM *rnd, BIGNUM *range);
+int	BN_rand_range(BIGNUM *rnd, const BIGNUM *range);
+int	BN_pseudo_rand_range(BIGNUM *rnd, const BIGNUM *range);
 int	BN_num_bits(const BIGNUM *a);
 int	BN_num_bits_word(BN_ULONG);
 BIGNUM *BN_new(void);
diff --git a/crypto/bn/bn_rand.c b/crypto/bn/bn_rand.c
index f51830b12..b376c28ff 100644
--- a/crypto/bn/bn_rand.c
+++ b/crypto/bn/bn_rand.c
@@ -227,7 +227,7 @@ int     BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
 
 
 /* random number r:  0 <= r < range */
-static int bn_rand_range(int pseudo, BIGNUM *r, BIGNUM *range)
+static int bn_rand_range(int pseudo, BIGNUM *r, const BIGNUM *range)
 	{
 	int (*bn_rand)(BIGNUM *, int, int, int) = pseudo ? BN_pseudo_rand : BN_rand;
 	int n;
@@ -294,12 +294,12 @@ static int bn_rand_range(int pseudo, BIGNUM *r, BIGNUM *range)
 	}
 
 
-int	BN_rand_range(BIGNUM *r, BIGNUM *range)
+int	BN_rand_range(BIGNUM *r, const BIGNUM *range)
 	{
 	return bn_rand_range(0, r, range);
 	}
 
-int	BN_pseudo_rand_range(BIGNUM *r, BIGNUM *range)
+int	BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range)
 	{
 	return bn_rand_range(1, r, range);
 	}