diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 17e0f90..222988c 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -1210,7 +1210,7 @@
 
 # The use of 'Server 1' in the DN is intentional here, as the DN is hardcoded in the x509_write test suite.'
 server5.req.ku.sha1: server5.key
-	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< key_usage=digital_signature,non_repudiation subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA1
+	$(OPENSSL) req -key $< -out $@ -new -nodes -subj "/C=NL/O=PolarSSL/CN=PolarSSL Server 1" -sha1 -addext keyUsage=digitalSignature,nonRepudiation
 all_final += server5.req.ku.sha1
 
 # server6*
diff --git a/tests/data_files/Readme-x509.txt b/tests/data_files/Readme-x509.txt
index 84c775f..82f93d2 100644
--- a/tests/data_files/Readme-x509.txt
+++ b/tests/data_files/Readme-x509.txt
@@ -76,6 +76,10 @@
     -badsign.crt: S5 with corrupted signature
     -expired.crt: S5 with "not after" date in the past
     -future.crt: S5 with "not before" date in the future
+    -non-compliant.crt: S5, RFC non-compliant
+      (with forbidden EC algorithm identifier NULL parameter)
+      generated by (before fix):
+        cert_write subject_key=server5.key subject_name="CN=Test EC RFC non-compliant" issuer_crt=test-ca2.crt issuer_key=test-ca2.key
     -selfsigned.crt: Self-signed cert with S5 key
     -ss-expired.crt: Self-signed cert with S5 key, expired
     -ss-forgeca.crt: Copy of test-int-ca3 self-signed with S5 key
diff --git a/tests/data_files/parse_input/server5-non-compliant.crt b/tests/data_files/parse_input/server5-non-compliant.crt
new file mode 100644
index 0000000..abea17d
--- /dev/null
+++ b/tests/data_files/parse_input/server5-non-compliant.crt
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/data_files/server5.req.ku.sha1 b/tests/data_files/server5.req.ku.sha1
index 3281c94..c73a0e2 100644
--- a/tests/data_files/server5.req.ku.sha1
+++ b/tests/data_files/server5.req.ku.sha1
@@ -1,8 +1,8 @@
 -----BEGIN CERTIFICATE REQUEST-----
-MIIBFjCBvAIBADA8MQswCQYDVQQGEwJOTDERMA8GA1UECgwIUG9sYXJTU0wxGjAY
+MIIBFDCBvAIBADA8MQswCQYDVQQGEwJOTDERMA8GA1UECgwIUG9sYXJTU0wxGjAY
 BgNVBAMMEVBvbGFyU1NMIFNlcnZlciAxMFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcD
 QgAEN8xW2XYJHlpyPsdZLf8gbu58+QaRdNCtFLX3aCJZYpJO5QDYIxH/6i/SNF1d
 Fr2KiMJrdw1VzYoqDvoByLTt/6AeMBwGCSqGSIb3DQEJDjEPMA0wCwYDVR0PBAQD
-AgbAMAsGByqGSM49BAEFAANIADBFAiEAnIKF+xKk0iEuN4MHd4FZWNvrznLQgkeg
-2n8ejjreTzcCIAH34z2TycuMpWQRhpV+YT988pBWR67LAg7REyZnjSAB
+AgbAMAkGByqGSM49BAEDSAAwRQIhAJyChfsSpNIhLjeDB3eBWVjb685y0IJHoNp/
+Ho463k83AiAB9+M9k8nLjKVkEYaVfmE/fPKQVkeuywIO0RMmZ40gAQ==
 -----END CERTIFICATE REQUEST-----
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index c796cdd..406a063 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -2890,6 +2890,14 @@
 depends_on:MBEDTLS_SHA256_C:MBEDTLS_RSA_C
 mbedtls_x509_crt_parse_file:"data_files/parse_input/cli-rsa-sha256-badalg.crt.der":MBEDTLS_ERR_X509_SIG_MISMATCH:0
 
+X509 File parse (does not conform to RFC 5480 / RFC 5758 - AlgorithmIdentifier's parameters field is present, mbedTLS generated before bugfix, OK)
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_SHA256_C
+x509parse_crt_file:"data_files/parse_input/server5-non-compliant.crt":0
+
+X509 File parse (conforms to RFC 5480 / RFC 5758 - AlgorithmIdentifier's parameters field must be absent for ECDSA)
+depends_on:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_SHA256_C
+x509parse_crt_file:"data_files/parse_input/server5.crt":0
+
 X509 Get time (UTC no issues)
 depends_on:MBEDTLS_X509_USE_C
 x509_get_time:MBEDTLS_ASN1_UTC_TIME:"500101000000Z":0:1950:1:1:0:0:0