diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 2ad5c2a..92c0f0b 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -1303,8 +1303,7 @@
 
 server1.req.sha256.ext: server1.key
 	# Generating this with OpenSSL as a comparison point to test we're getting the same result
-	openssl req -new -out $@ -key $< -subj '/C=NL/O=PolarSSL/CN=PolarSSL Server 1' -sha256 -addext "extendedKeyUsage=serverAuth" -addext "subjectAltName=URI:http://pki.example.com/,IP:127.1.1.0,DNS:example.com"
-all_final += server1.req.sha256.ext
+	openssl req -new -out $@ -key $< -subj '/C=NL/O=PolarSSL/CN=PolarSSL Server 1' -sha256 -config server1.req.sha256.conf
 
 parse_input/server1.req.sha384 server1.req.sha384: server1.key
 	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA384
diff --git a/tests/data_files/server1.req.sha256.conf b/tests/data_files/server1.req.sha256.conf
new file mode 100644
index 0000000..0d35818
--- /dev/null
+++ b/tests/data_files/server1.req.sha256.conf
@@ -0,0 +1,17 @@
+req_extensions = req_ext
+
+[req_ext]
+extendedKeyUsage = serverAuth
+subjectAltName = @alt_names
+
+[alt_names]
+email = mail@example.com
+DNS = example.com
+dirName = dirname_sect
+IP = 127.0.0.1
+URI = http://pki.example.com
+
+[dirname_sect]
+C=UK
+O=Mbed TLS
+CN=Mbed TLS directoryName SAN
diff --git a/tests/data_files/server1.req.sha256.ext b/tests/data_files/server1.req.sha256.ext
index c5ff5c5..1bb05da 100644
--- a/tests/data_files/server1.req.sha256.ext
+++ b/tests/data_files/server1.req.sha256.ext
@@ -1,18 +1,20 @@
 -----BEGIN CERTIFICATE REQUEST-----
-MIIC3jCCAcYCAQAwPDELMAkGA1UEBhMCTkwxETAPBgNVBAoMCFBvbGFyU1NMMRow
+MIIDPzCCAicCAQAwPDELMAkGA1UEBhMCTkwxETAPBgNVBAoMCFBvbGFyU1NMMRow
 GAYDVQQDDBFQb2xhclNTTCBTZXJ2ZXIgMTCCASIwDQYJKoZIhvcNAQEBBQADggEP
 ADCCAQoCggEBAKkCHz1AatVVU4v9Nu6CZS4VYV6Jv7joRZDb7ogWUtPxQ1BHlhJZ
 ZIdr/SvgRvlzvt3PkuGRW+1moG+JKXlFgNCDatVBQ3dfOXwJBEeCsFc5cO2j7BUZ
 HqgzCEfBBUKp/UzDtN/dBh9NEFFAZ3MTD0D4bYElXwqxU8YwfhU5rPla7n+SnqYF
 W+cTl4W1I5LZ1CQG1QkliXUH3aYajz8JGb6tZSxk65Wb3P5BXhem2mxbacwCuhQs
 FiScStzN0PdSZ3PxLaAj/X70McotcMqJCwTbLqZPcG6ezr1YieJTWZ5uWpJl4og/
-DJQZo93l6J2VE+0p26twEtxaymsXq1KCVLECAwEAAaBdMFsGCSqGSIb3DQEJDjFO
-MEwwEwYDVR0lBAwwCgYIKwYBBQUHAwEwNQYDVR0RBC4wLIYXaHR0cDovL3BraS5l
-eGFtcGxlLmNvbS+HBH8BAQCCC2V4YW1wbGUuY29tMA0GCSqGSIb3DQEBCwUAA4IB
-AQCGmTIXEUvTqwChkzRtxPIQDDchrMnCXgUrTSxre5nvUOpjVlcIIPGWAwxRovfe
-pW6OaGZ/3xD0dRAcOW08sTD6GRUazFrubPA1eZiNC7vYdWV59qm84N5yRR/s8Hm+
-okwI47m7W9C0pfaNXchgFUQBn16TrZxPXklbCpBJ/TFV+1ODY0sJPHYiCFpYI+Jz
-YuJmadP2BHucl8wv2RyVHywOmV1sDc74i9igVrBCAh8wu+kqImMtrnkGZDxrnj/L
-5P1eDfdqG2cN+s40RnMQMosh3UfqpNV/bTgAqBPP2uluT9L1KpWcjZeuvisOgVTq
-XwFI5s34fen2DUVw6MWNfbDK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 -----END CERTIFICATE REQUEST-----
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index ab4a2d0..b4073ec 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -153,24 +153,44 @@
     mbedtls_x509_san_list san_ip;
     mbedtls_x509_san_list san_dns;
     mbedtls_x509_san_list san_uri;
+    mbedtls_x509_san_list san_mail;
+    mbedtls_x509_san_list san_dn;
     mbedtls_x509_san_list *san_list = NULL;
-    const char san_ip_name[] = { 0x7f, 0x01, 0x01, 0x00 }; // 127.1.1.0
+    mbedtls_asn1_named_data *ext_san_dirname = NULL;
+
+    const char san_ip_name[] = { 0x7f, 0x00, 0x00, 0x01 }; // 127.0.0.1
     const char *san_dns_name = "example.com";
-    const char *san_uri_name = "http://pki.example.com/";
+    const char *san_dn_name = "C=UK,O=Mbed TLS,CN=Mbed TLS directoryName SAN";
+    const char *san_mail_name = "mail@example.com";
+    const char *san_uri_name = "http://pki.example.com";
+
+    san_mail.node.type = MBEDTLS_X509_SAN_RFC822_NAME;
+    san_mail.node.san.unstructured_name.p = (unsigned char *) san_mail_name;
+    san_mail.node.san.unstructured_name.len = strlen(san_mail_name);
+    san_mail.next = NULL;
+
+    san_dns.node.type = MBEDTLS_X509_SAN_DNS_NAME;
+    san_dns.node.san.unstructured_name.p = (unsigned char *) san_dns_name;
+    san_dns.node.san.unstructured_name.len = strlen(san_dns_name);
+    san_dns.next = &san_mail;
+
+    san_dn.node.type = MBEDTLS_X509_SAN_DIRECTORY_NAME;
+    TEST_ASSERT(mbedtls_x509_string_to_names(&ext_san_dirname,
+                                             san_dn_name) == 0);
+    san_dn.node.san.directory_name = *ext_san_dirname;
+    san_dn.next = &san_dns;
+
+    san_ip.node.type = MBEDTLS_X509_SAN_IP_ADDRESS;
+    san_ip.node.san.unstructured_name.p = (unsigned char *) san_ip_name;
+    san_ip.node.san.unstructured_name.len = sizeof(san_ip_name);
+    san_ip.next = &san_dn;
 
     san_uri.node.type = MBEDTLS_X509_SAN_UNIFORM_RESOURCE_IDENTIFIER;
     san_uri.node.san.unstructured_name.p = (unsigned char *) san_uri_name;
     san_uri.node.san.unstructured_name.len = strlen(san_uri_name);
-    san_uri.next = NULL;
-    san_ip.node.type = MBEDTLS_X509_SAN_IP_ADDRESS;
-    san_ip.node.san.unstructured_name.p = (unsigned char *) san_ip_name;
-    san_ip.node.san.unstructured_name.len = sizeof(san_ip_name);
-    san_ip.next = &san_uri;
-    san_dns.node.type = MBEDTLS_X509_SAN_DNS_NAME;
-    san_dns.node.san.unstructured_name.p = (unsigned char *) san_dns_name;
-    san_dns.node.san.unstructured_name.len = strlen(san_dns_name);
-    san_dns.next = &san_ip;
-    san_list = &san_dns;
+    san_uri.next = &san_ip;
+
+    san_list = &san_uri;
 
     memset(&rnd_info, 0x2a, sizeof(mbedtls_test_rnd_pseudo_info));