diff --git a/expat/lib/xmlparse.c b/expat/lib/xmlparse.c
--- a/expat/lib/xmlparse.c
+++ b/expat/lib/xmlparse.c
@@ -3458,6 +3458,9 @@ storeAtts(XML_Parser parser, const ENCOD
   int n;
   XML_Char *uri;
   int nPrefixes = 0;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+  int nXMLNSDeclarations = 0;
+/* END MOZILLA CHANGE */
   BINDING *binding;
   const XML_Char *localPart;
 
@@ -3615,7 +3618,15 @@ storeAtts(XML_Parser parser, const ENCOD
                                            appAtts[attIndex], bindingsPtr);
         if (result)
           return result;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+#if 0
         --attIndex;
+#else
+        attIndex++;
+        nXMLNSDeclarations++;
+        (attId->name)[-1] = 3;
+#endif
+/* END MOZILLA CHANGE */
       } else {
         /* deal with other prefixed names later */
         attIndex++;
@@ -3647,6 +3658,12 @@ storeAtts(XML_Parser parser, const ENCOD
                                              da->value, bindingsPtr);
           if (result)
             return result;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+          (da->id->name)[-1] = 3;
+          nXMLNSDeclarations++;
+          appAtts[attIndex++] = da->id->name;
+          appAtts[attIndex++] = da->value;
+/* END MOZILLA CHANGE */
         } else {
           (da->id->name)[-1] = 2;
           nPrefixes++;
@@ -3665,7 +3682,13 @@ storeAtts(XML_Parser parser, const ENCOD
   /* expand prefixed attribute names, check for duplicates,
      and clear flags that say whether attributes were specified */
   i = 0;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+#if 0
   if (nPrefixes) {
+#else
+  if (nPrefixes || nXMLNSDeclarations) {
+#endif
+/* END MOZILLA CHANGE */
     int j; /* hash table index */
     unsigned long version = parser->m_nsAttsVersion;
 
@@ -3675,6 +3698,9 @@ storeAtts(XML_Parser parser, const ENCOD
     }
 
     unsigned int nsAttsSize = 1u << parser->m_nsAttsPower;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+    if (nPrefixes) {
+/* END MOZILLA CHANGE */
     unsigned char oldNsAttsPower = parser->m_nsAttsPower;
     /* size of hash table must be at least 2 * (# of prefixed attributes) */
     if ((nPrefixes << 1)
@@ -3724,6 +3750,9 @@ storeAtts(XML_Parser parser, const ENCOD
         parser->m_nsAtts[--j].version = version;
     }
     parser->m_nsAttsVersion = --version;
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+    }
+/* END MOZILLA CHANGE */
 
     /* expand prefixed names and check for duplicates */
     for (; i < attIndex; i += 2) {
@@ -3823,10 +3852,63 @@ storeAtts(XML_Parser parser, const ENCOD
         parser->m_nsAtts[j].hash = uriHash;
         parser->m_nsAtts[j].uriName = s;
 
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+#if 0
         if (! --nPrefixes) {
+#else
+        if (! --nPrefixes && ! nXMLNSDeclarations) {
+#endif
+/* END MOZILLA CHANGE */
           i += 2;
           break;
         }
+/* BEGIN MOZILLA CHANGE (Include xmlns attributes in attributes array) */
+      } else if (s[-1] == 3) { /* xmlns attribute */
+        static const XML_Char xmlnsNamespace[] = {
+          ASCII_h, ASCII_t, ASCII_t, ASCII_p, ASCII_COLON, ASCII_SLASH, ASCII_SLASH,
+          ASCII_w, ASCII_w, ASCII_w, ASCII_PERIOD, ASCII_w, ASCII_3, ASCII_PERIOD,
+          ASCII_o, ASCII_r, ASCII_g, ASCII_SLASH, ASCII_2, ASCII_0, ASCII_0, ASCII_0,
+          ASCII_SLASH, ASCII_x, ASCII_m, ASCII_l, ASCII_n, ASCII_s, ASCII_SLASH, '\0'
+        };
+        static const XML_Char xmlnsPrefix[] = {
+          ASCII_x, ASCII_m, ASCII_l, ASCII_n, ASCII_s, '\0'
+        };
+
+        ((XML_Char *)s)[-1] = 0;  /* clear flag */
+        if (! poolAppendString(&parser->m_tempPool, xmlnsNamespace)
+            || ! poolAppendChar(&parser->m_tempPool, parser->m_namespaceSeparator))
+          return XML_ERROR_NO_MEMORY;
+        s += sizeof(xmlnsPrefix) / sizeof(xmlnsPrefix[0]) - 1;
+        if (*s == XML_T(':')) {
+          ++s;
+          do {  /* copies null terminator */
+            if (! poolAppendChar(&parser->m_tempPool, *s))
+              return XML_ERROR_NO_MEMORY;
+          } while (*s++);
+          if (parser->m_ns_triplets) { /* append namespace separator and prefix */
+            parser->m_tempPool.ptr[-1] = parser->m_namespaceSeparator;
+            if (! poolAppendString(&parser->m_tempPool, xmlnsPrefix)
+                || ! poolAppendChar(&parser->m_tempPool, '\0'))
+              return XML_ERROR_NO_MEMORY;
+          }
+        }
+        else {
+          /* xlmns attribute without a prefix. */
+          if (! poolAppendString(&parser->m_tempPool, xmlnsPrefix)
+              || ! poolAppendChar(&parser->m_tempPool, '\0'))
+            return XML_ERROR_NO_MEMORY;
+        }
+
+        /* store expanded name in attribute list */
+        s = poolStart(&parser->m_tempPool);
+        poolFinish(&parser->m_tempPool);
+        appAtts[i] = s;
+
+        if (! --nXMLNSDeclarations && ! nPrefixes) {
+          i += 2;
+          break;
+        }
+/* END MOZILLA CHANGE */
       } else                     /* not prefixed */
         ((XML_Char *)s)[-1] = 0; /* clear flag */
     }