diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 882dc71..e69aa27 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -3315,9 +3315,9 @@
         ssl->handshake->pmslen =
             MBEDTLS_PSA_ECC_KEY_BYTES_OF_CURVE( handshake->ecdh_psa_curve );
 
-        status = psa_generator_read( &generator,
-                                     ssl->handshake->premaster,
-                                     ssl->handshake->pmslen );
+        status = psa_key_derivation_output_bytes( &generator,
+                                                  ssl->handshake->premaster,
+                                                  ssl->handshake->pmslen );
         if( status != PSA_SUCCESS )
         {
             psa_generator_abort( &generator );