diff --git a/src/java/com/wolfssl/provider/jsse/WolfSSLX509.java b/src/java/com/wolfssl/provider/jsse/WolfSSLX509.java
index c375af7..52d62d1 100644
--- a/src/java/com/wolfssl/provider/jsse/WolfSSLX509.java
+++ b/src/java/com/wolfssl/provider/jsse/WolfSSLX509.java
@@ -698,7 +698,7 @@ public class WolfSSLX509 extends X509Certificate {
         private String[] DNs = { "/emailAddress=", "/CN=", "/OU=",
                 "/O=", "/L=", "/ST=", "/C="};
 
-        /* replace the wolfSSL version of the tag. Returns replacement
+        /* Replace the wolfSSL version of the tag. Returns replacement
          * on success. */
         private String getReplace(String in) {
             if (in.equals("/emailAddress=")) {
@@ -725,53 +725,51 @@ public class WolfSSLX509 extends X509Certificate {
             return null;
         }
 
-        /* check if the string starts with an expected tag.
-         * returns index into DNs of tag when found */
-        private int containsDN(String in) {
-            int i;
-            for (i = 0; i < DNs.length; i++) {
-                if (in.startsWith(DNs[i]))
-                    return i;
+        /* Map "TAG=value" component to its JSSE spelling, leaving
+         * unrecognized tags unchanged. */
+        private String mapComponent(String component) {
+            for (int i = 0; i < DNs.length; i++) {
+                /* DNs entries carry a leading '/', drop it to compare */
+                String tag = DNs[i].substring(1);
+                if (component.startsWith(tag)) {
+                    String replace = getReplace(DNs[i]);
+                    if (replace != null) {
+                        return replace.concat(
+                            component.substring(tag.length()));
+                    }
+                }
             }
-            return -1;
+            return component;
         }
 
-        /* convert name from having "/DN=" format to "DN= ," format
+        /* Convert name from having "/DN=" format to "DN= ," format
          * returns the new reformatted string on success */
         private String reformatList(String in) {
-            String[] ret;
-            int i, j;
-            String tmp = in;
-            ArrayList<String> list = new ArrayList<String>();
-
             if (in == null) {
                 return null;
             }
 
-            ret = in.split("/");
-
-            while (tmp.length() > 3) {
-                for (i = tmp.length() - 3; i >= 0; i--) {
-                    if ((j = containsDN(in.substring(i))) >= 0) {
-                        String current = tmp.substring(i, tmp.length());
-                        current = current.replaceAll(DNs[j],
-                                                     getReplace(DNs[j]));
-                        list.add(current);
-                        tmp = tmp.substring(0, i);
-                        break;
-                    }
+            /* Split before each '/' followed by a "TAG=" attribute type,
+             * then reverse the RDN order. wolfSSL does not escape '/', so
+             * '/' inside a value followed by "TAG=" will split too.
+             * Unrecognized RDN types pass through unchanged. */
+            String[] parts = in.split("/(?=[A-Za-z0-9.]+=)");
+            ArrayList<String> list = new ArrayList<String>();
+            for (int i = 0; i < parts.length; i++) {
+                if (!parts[i].isEmpty()) {
+                    list.add(mapComponent(parts[i]));
                 }
             }
 
-            ret = list.toArray(new String[list.size()]);
-            tmp = "";
-            for (i = 0; i < ret.length - 1; i++) {
-                tmp = tmp.concat(ret[i]);
-                tmp = tmp.concat(", ");
+            StringBuilder sb = new StringBuilder();
+            for (int i = list.size() - 1; i >= 0; i--) {
+                sb.append(list.get(i));
+                if (i > 0) {
+                    sb.append(", ");
+                }
             }
-            tmp = tmp.concat(ret[i]);
 
-            return tmp;
+            return sb.toString();
         }
 
         private WolfSSLPrincipal(String in) {
diff --git a/src/test/com/wolfssl/provider/jsse/test/WolfSSLX509Test.java b/src/test/com/wolfssl/provider/jsse/test/WolfSSLX509Test.java
index e334ac5..2f0e441 100644
--- a/src/test/com/wolfssl/provider/jsse/test/WolfSSLX509Test.java
+++ b/src/test/com/wolfssl/provider/jsse/test/WolfSSLX509Test.java
@@ -49,6 +49,7 @@ import java.security.cert.CertificateException;
 import java.security.cert.CertificateExpiredException;
 import java.security.cert.CertificateNotYetValidException;
 import java.security.cert.X509Certificate;
+import java.util.Base64;
 import java.util.Date;
 import java.util.Set;
 import java.util.List;
@@ -116,6 +117,62 @@ public class WolfSSLX509Test {
         subjectDN = x509.getSubjectDN();
     }
 
+    /* Self-signed cert whose subject and issuer use DC (domainComponent)
+     * RDNs, an attribute type outside the reformat tag table.
+     * DN: DC=com, DC=example, CN=test.example.com */
+    private static final String DC_RDN_CERT_DER =
+        "MIIDczCCAlugAwIBAgIUJvqgr93mm9aonQB+pyzrjyu7TBowDQYJKoZIhvcN" +
+        "AQELBQAwSTETMBEGCgmSJomT8ixkARkWA2NvbTEXMBUGCgmSJomT8ixkARkW" +
+        "B2V4YW1wbGUxGTAXBgNVBAMMEHRlc3QuZXhhbXBsZS5jb20wHhcNMjYwODI0" +
+        "MjA0NjUyWhcNMzYwODIxMjA0NjUyWjBJMRMwEQYKCZImiZPyLGQBGRYDY29t" +
+        "MRcwFQYKCZImiZPyLGQBGRYHZXhhbXBsZTEZMBcGA1UEAwwQdGVzdC5leGFt" +
+        "cGxlLmNvbTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBALAo9F5Q" +
+        "xsEOHMFK0sNiHi5HUscCQWtFxA5AlH9mqfgSAYbEpm9YmHbvgBH2Mvc5vEZY" +
+        "hB1CRQT7pipS4iXUG+7cnz7M8YyKUuh5TtQTIARaPu2ZpTHOxQ2QMip/eHsI" +
+        "l8IggiVZZuJcnXHj1nrB8pcx4wreXyi+7r7INViffNV61bGOes6ftIH/sptD" +
+        "Sw0CXQUf1KfiM1rXaXw8cezYmmJWFoie0R6tbrMEfTRAKb1j4IEqWa3e7Krq" +
+        "+bZEmiw5kfP2vlEW2w+TylNWOm7uQu742VAJnIqgZ3nnVPxqd/5Ef5E8sMmI" +
+        "Xy/F+rhEFxZtmAiDnBflmPypXSp0w5c01P0CAwEAAaNTMFEwHQYDVR0OBBYE" +
+        "FPHoxpJFtgM3/ntZjdyu3Zy2CtSnMB8GA1UdIwQYMBaAFPHoxpJFtgM3/ntZ" +
+        "jdyu3Zy2CtSnMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQELBQADggEB" +
+        "AJvFrnuTfU9MNTRCJGM3JAyex5RK3g5/SOs6uBjM8A1oM5NzTuZrjQzFWMtd" +
+        "srS8HMIoatKOxGYJUU1OHy4JpfF6Rfv38+q6QuugemIGmDjBEqmO100ZoYgF" +
+        "ppujEABELIyMpvqp48e6U8uo1mRoK8BWp4KeZiPo7jzi32HoDkeu+ZUNvn1G" +
+        "0DwgDiYl5ailSofBKplprpI77hx11fypekatWqsfR01Q/0OEkSsj/gO50em1" +
+        "VAMUYB1v8WXAivovfkUjx+J8xaund6Tx595jTHMOpQMckM/4C2ecvmixEKrF" +
+        "uz8gim9WCP+Pe6WZI948Kia+btaslCf58Y6/qrgJTJE=";
+
+    @Test
+    public void testGetSubjectIssuerDNUnrecognizedRdnTerminates()
+        throws Exception {
+
+        Assume.assumeTrue(WolfSSL.RsaEnabled());
+
+        byte[] der = Base64.getDecoder().decode(DC_RDN_CERT_DER);
+        final WolfSSLX509 cert = new WolfSSLX509(der);
+
+        /* Reversed DN, matching getSubjectX500Principal() output. */
+        final String expected = "CN=test.example.com, DC=example, DC=com";
+        final String[] result = new String[2];
+
+        /* Run in a worker thread so a non-terminating reformat shows up as
+         * a still-alive thread instead of hanging the whole test run. */
+        Thread worker = new Thread(new Runnable() {
+            public void run() {
+                result[0] = cert.getSubjectDN().getName();
+                result[1] = cert.getIssuerDN().getName();
+            }
+        });
+        worker.setDaemon(true);
+        worker.start();
+        worker.join(5000);
+
+        assertFalse("getSubjectDN/getIssuerDN did not terminate on an " +
+            "unrecognized RDN type", worker.isAlive());
+        assertEquals(expected, result[0]);
+        assertEquals(expected, result[1]);
+    }
+
     @Test
     public void testServerParsing() {
         try {