diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 831cc52ac0..c43f95ee1b 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3182,12 +3182,6 @@ static int ssl_conf_check(const mbedtls_ssl_context *ssl)
     if( ret != 0 )
         return( ret );
 
-    if( ssl->conf->f_rng == NULL )
-    {
-        MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided" ) );
-        return( MBEDTLS_ERR_SSL_NO_RNG );
-    }
-
     /* Space for further checks */
 
     return( 0 );
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 0a07e06c40..f5a6e20cab 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -116,6 +116,12 @@ static int ssl_tls13_prepare_client_hello( mbedtls_ssl_context *ssl )
 {
     int ret;
 
+    if( ssl->conf->f_rng == NULL )
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "no RNG provided" ) );
+        return( MBEDTLS_ERR_SSL_NO_RNG );
+    }
+
     if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng,
                                   ssl->handshake->randbytes,
                                   CLIENT_HELLO_RAND_BYTES_LEN ) ) != 0 )