diff --git a/crypto/fipsmodule/ec/ec_key.c b/crypto/fipsmodule/ec/ec_key.c
index fcdc687..0d9ce67 100644
--- a/crypto/fipsmodule/ec/ec_key.c
+++ b/crypto/fipsmodule/ec/ec_key.c
@@ -394,7 +394,7 @@
   return ok;
 }
 
-size_t EC_KEY_key2buf(EC_KEY *key, point_conversion_form_t form,
+size_t EC_KEY_key2buf(const EC_KEY *key, point_conversion_form_t form,
                       unsigned char **out_buf, BN_CTX *ctx) {
   if (key == NULL || key->pub_key == NULL || key->group == NULL) {
     return 0;
diff --git a/include/openssl/ec.h b/include/openssl/ec.h
index fcecb62..cfad93e 100644
--- a/include/openssl/ec.h
+++ b/include/openssl/ec.h
@@ -223,8 +223,14 @@
 
 // EC_POINT_set_affine_coordinates_GFp sets the value of |point| to be
 // (|x|, |y|). The |ctx| argument may be used if not NULL. It returns one
-// on success or zero on error. Note that, unlike with OpenSSL, it's
-// considered an error if the point is not on the curve.
+// on success or zero on error. It's considered an error if the point is not on
+// the curve.
+//
+// Note that the corresponding function in OpenSSL versions prior to 1.0.2s does
+// not check if the point is on the curve. This is a security-critical check, so
+// code additionally supporting OpenSSL should repeat the check with
+// |EC_POINT_is_on_curve| or check for older OpenSSL versions with
+// |OPENSSL_VERSION_NUMBER|.
 OPENSSL_EXPORT int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group,
                                                        EC_POINT *point,
                                                        const BIGNUM *x,
@@ -248,8 +254,9 @@
                                       BN_CTX *ctx);
 
 // EC_POINT_oct2point sets |point| from |len| bytes of X9.62 format
-// serialisation in |buf|. It returns one on success and zero otherwise. The
-// |ctx| argument may be used if not NULL.
+// serialisation in |buf|. It returns one on success and zero on error. The
+// |ctx| argument may be used if not NULL. It's considered an error if |buf|
+// does not represent a point on the curve.
 OPENSSL_EXPORT int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *point,
                                       const uint8_t *buf, size_t len,
                                       BN_CTX *ctx);
diff --git a/include/openssl/ec_key.h b/include/openssl/ec_key.h
index 1bc6d30..932ad8e 100644
--- a/include/openssl/ec_key.h
+++ b/include/openssl/ec_key.h
@@ -172,7 +172,8 @@
 OPENSSL_EXPORT int EC_KEY_check_fips(const EC_KEY *key);
 
 // EC_KEY_set_public_key_affine_coordinates sets the public key in |key| to
-// (|x|, |y|). It returns one on success and zero otherwise.
+// (|x|, |y|). It returns one on success and zero on error. It's considered an
+// error if |x| and |y| do not represent a point on |key|'s curve.
 OPENSSL_EXPORT int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key,
                                                             const BIGNUM *x,
                                                             const BIGNUM *y);
@@ -180,7 +181,8 @@
 // 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
 // octet string or zero if an error occurred.
-OPENSSL_EXPORT size_t EC_KEY_key2buf(EC_KEY *key, point_conversion_form_t form,
+OPENSSL_EXPORT size_t EC_KEY_key2buf(const EC_KEY *key,
+                                     point_conversion_form_t form,
                                      unsigned char **out_buf, BN_CTX *ctx);