s/set1/assign/
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py
index 3d00021..a68bc08 100644
--- a/cryptography/hazmat/backends/openssl/backend.py
+++ b/cryptography/hazmat/backends/openssl/backend.py
@@ -315,7 +315,7 @@
         res = self._lib.RSA_blinding_on(rsa_cdata, self._ffi.NULL)
         assert res == 1
 
-        res = self._lib.EVP_PKEY_set1_RSA(evp_pkey, rsa_cdata)
+        res = self._lib.EVP_PKEY_assign_RSA(evp_pkey, rsa_cdata)
         assert res == 1
 
         return evp_pkey
@@ -327,7 +327,7 @@
         res = self._lib.RSA_blinding_on(rsa_cdata, self._ffi.NULL)
         assert res == 1
 
-        res = self._lib.EVP_PKEY_set1_RSA(evp_pkey, rsa_cdata)
+        res = self._lib.EVP_PKEY_assign_RSA(evp_pkey, rsa_cdata)
         assert res == 1
 
         return evp_pkey