diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index f916b1c..9352c9e 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -76,7 +76,9 @@
     int ret;
     size_t olen = sizeof( check_buf );
     FILE *f;
+    rnd_pseudo_info rnd_info;
 
+    memset( &rnd_info, 0x2a, sizeof( rnd_pseudo_info ) );
     mpi_init( &serial );
     pk_init( &subject_key );
     pk_init( &issuer_key );
@@ -101,7 +103,8 @@
     TEST_ASSERT( x509write_crt_set_subject_key_identifier( &crt ) == 0 );
     TEST_ASSERT( x509write_crt_set_authority_key_identifier( &crt ) == 0 );
 
-    ret = x509write_crt_der( &crt, buf, sizeof(buf) );
+    ret = x509write_crt_der( &crt, buf, sizeof(buf),
+                             rnd_pseudo_rand, &rnd_info );
     TEST_ASSERT( ret >= 0 );
 
     c = buf + sizeof( buf ) - ret;