diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index 8407a65..d93c171 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -618,6 +618,7 @@
     TEST_ASSERT(ret == MBEDTLS_ERR_ASN1_BUF_TOO_SMALL);
 
 exit:
+    mbedtls_asn1_free_named_data_list(&ext_san_dirname);
     mbedtls_x509write_crt_free(&crt);
     mbedtls_pk_free(&issuer_key_alt);
     mbedtls_pk_free(&subject_key);