diff --git a/crypto/fipsmodule/ec/ec_key.c b/crypto/fipsmodule/ec/ec_key.c
index 3851c19..fcdc687 100644
--- a/crypto/fipsmodule/ec/ec_key.c
+++ b/crypto/fipsmodule/ec/ec_key.c
@@ -369,8 +369,8 @@
   return 1;
 }
 
-int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
-                                             BIGNUM *y) {
+int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, const BIGNUM *x,
+                                             const BIGNUM *y) {
   EC_POINT *point = NULL;
   int ok = 0;
 
diff --git a/include/openssl/ec_key.h b/include/openssl/ec_key.h
index 3b1a566..be0faaf8 100644
--- a/include/openssl/ec_key.h
+++ b/include/openssl/ec_key.h
@@ -174,8 +174,8 @@
 // EC_KEY_set_public_key_affine_coordinates sets the public key in |key| to
 // (|x|, |y|). It returns one on success and zero otherwise.
 OPENSSL_EXPORT int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key,
-                                                            BIGNUM *x,
-                                                            BIGNUM *y);
+                                                            const BIGNUM *x,
+                                                            const BIGNUM *y);
 
 // EC_KEY_key2buf encodes the public key in |key| to an allocated octet string
 // and sets |*out_buf| to point to it. It returns the length of the encoded