diff --git a/tests/suites/test_suite_x509write.data b/tests/suites/test_suite_x509write.data
index 490df80..77ac53a 100644
--- a/tests/suites/test_suite_x509write.data
+++ b/tests/suites/test_suite_x509write.data
@@ -205,16 +205,19 @@
 X509 String to Names #13 (Invalid hexpair escape at end of string)
 mbedtls_x509_string_to_names:"C=NL, O=\\4f\\66\\66\\73\\70\\61\\72\\6, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
 
-X509 String to Names #14 (Escape non-ascii hexpairs)
+X509 String to Names #14 (Reject escaped null hexpair)
+mbedtls_x509_string_to_names:"C=NL, O=Of\\00spark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
+
+X509 String to Names #15 (Escape non-ascii hexpairs)
 mbedtls_x509_string_to_names:"C=NL, O=Of\\00spark, OU=PolarSSL":"C=NL, O=Of\\00spark, OU=PolarSSL":0
 
-X509 String to Names #15 (Invalid hexpairs)
+X509 String to Names #16 (Invalid hexpairs)
 mbedtls_x509_string_to_names:"C=NL, O=Of\\flspark, OU=PolarSSL":"":MBEDTLS_ERR_X509_INVALID_NAME
 
-X509 String to Names #16 (Accept numercoid/hexstring)
+X509 String to Names #17 (Accept numercoid/hexstring)
 mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#0C084F6666737061726B, OU=PolarSSL":"C=NL, O=Offspark, OU=PolarSSL":0
 
-X509 String to Names #17 (Output attributetype as bitstring)
+X509 String to Names #18 (Output attributetype as bitstring)
 mbedtls_x509_string_to_names:"C=NL, 2.5.4.10=#03084F6666737061726B, OU=PolarSSL":"C=NL, O=#03084F6666737061726B, OU=PolarSSL":0
 
 Check max serial length