diff --git a/mozilla/expat/xmlparse/xmlparse.h b/mozilla/expat/xmlparse/xmlparse.h
index 8c1d95d0a3d..589fe366f69 100644
--- a/mozilla/expat/xmlparse/xmlparse.h
+++ b/mozilla/expat/xmlparse/xmlparse.h
@@ -411,7 +411,7 @@ The new parser is completely independent and may safely be used in a separate th
 The handlers and userData are initialized from the parser argument.
 Returns 0 if out of memory.  Otherwise returns a new XML_Parser object. */
 
-#if 0
+#if 1
 #define XML_DTD
 #endif /* 0 */
 
diff --git a/mozilla/expat/xmltok/xmltok.h b/mozilla/expat/xmltok/xmltok.h
index abf682ade57..96d521867ff 100644
--- a/mozilla/expat/xmltok/xmltok.h
+++ b/mozilla/expat/xmltok/xmltok.h
@@ -108,7 +108,7 @@ extern "C" {
    for a name with a colon. */
 #define XML_TOK_PREFIXED_NAME 41
 
-#if 0
+#if 1
 #define XML_DTD
 #endif /* 0 */
 
diff --git a/mozilla/parser/expat/lib/xmlparse.h b/mozilla/parser/expat/lib/xmlparse.h
index 8c1d95d0a3d..589fe366f69 100644
--- a/mozilla/parser/expat/lib/xmlparse.h
+++ b/mozilla/parser/expat/lib/xmlparse.h
@@ -411,7 +411,7 @@ The new parser is completely independent and may safely be used in a separate th
 The handlers and userData are initialized from the parser argument.
 Returns 0 if out of memory.  Otherwise returns a new XML_Parser object. */
 
-#if 0
+#if 1
 #define XML_DTD
 #endif /* 0 */
 
diff --git a/mozilla/parser/expat/lib/xmltok.h b/mozilla/parser/expat/lib/xmltok.h
index abf682ade57..96d521867ff 100644
--- a/mozilla/parser/expat/lib/xmltok.h
+++ b/mozilla/parser/expat/lib/xmltok.h
@@ -108,7 +108,7 @@ extern "C" {
    for a name with a colon. */
 #define XML_TOK_PREFIXED_NAME 41
 
-#if 0
+#if 1
 #define XML_DTD
 #endif /* 0 */