1 files changed, 2 insertions, 2 deletions

diff --git a/src/lib/libcrypto/bn/bn_add.c b/src/lib/libcrypto/bn/bn_add.c
index c5ab066c9e..5d24691233 100644
--- a/src/lib/libcrypto/bn/bn_add.c
+++ b/src/lib/libcrypto/bn/bn_add.c
@@ -61,9 +61,9 @@
 #include "bn_lcl.h"
 
 /* r can == a or b */
-int BN_add(BIGNUM *r, BIGNUM *a, BIGNUM *b)
+int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
         {
-        BIGNUM *tmp;
+        const BIGNUM *tmp;
 
         bn_check_top(a);
         bn_check_top(b);