diff --git a/docs/GNUmakefile b/docs/GNUmakefile
index aea6760..7c72b91 100644
--- a/docs/GNUmakefile
+++ b/docs/GNUmakefile
@@ -12,22 +12,26 @@
 		$(TEMP)/$(NGINX)/CHANGES
 
 
-$(TEMP)/$(NGINX)/CHANGES.ru:	docs/xml/nginx/changes.xml		\
+$(TEMP)/$(NGINX)/CHANGES.ru:	docs/dtd/changes.dtd			\
+				docs/xml/nginx/changes.xml		\
 				docs/xml/change_log_conf.xml		\
 				docs/xslt/changes.xslt
 
 	mkdir -p $(TEMP)/$(NGINX)
 
+	xmllint --noout --valid docs/xml/nginx/changes.xml
 	xsltproc --stringparam lang ru					\
 		-o $@ docs/xslt/changes.xslt docs/xml/nginx/changes.xml
 
 
-$(TEMP)/$(NGINX)/CHANGES:	docs/xml/nginx/changes.xml		\
+$(TEMP)/$(NGINX)/CHANGES:	docs/dtd/changes.dtd			\
+				docs/xml/nginx/changes.xml		\
 				docs/xml/change_log_conf.xml		\
 				docs/xslt/changes.xslt
 
 	mkdir -p $(TEMP)/$(NGINX)
 
+	xmllint --noout --valid docs/xml/nginx/changes.xml
 	xsltproc --stringparam lang en					\
 		-o $@ docs/xslt/changes.xslt docs/xml/nginx/changes.xml
 
diff --git a/docs/dtd/changes.dtd b/docs/dtd/changes.dtd
index 4dea2c7..e14518a 100644
--- a/docs/dtd/changes.dtd
+++ b/docs/dtd/changes.dtd
@@ -12,10 +12,10 @@
 >
 
 <!ELEMENT change       (para)* >
-<!ATTLIST change       type (bugfix | feature | change | workaround) #IMPLIED >
+<!ATTLIST change       type (bugfix | feature | change | security | workaround) #IMPLIED >
 
 <!ELEMENT para         (#PCDATA | at | br | nobr)* >
-<!ATTLIST para         lang (ru | en) #IMPLIED >
+<!ATTLIST para         lang (ru | en) #REQUIRED >
 
 <!ELEMENT at           EMPTY >
 <!ELEMENT br           EMPTY >
diff --git a/docs/xml/nginx/changes.xml b/docs/xml/nginx/changes.xml
index af5ea7c..cc475da 100644
--- a/docs/xml/nginx/changes.xml
+++ b/docs/xml/nginx/changes.xml
@@ -2,11 +2,7 @@
 <!DOCTYPE change_log SYSTEM "../../dtd/changes.dtd" >
 
 
-<change_log link="/nginx/changes.html" path="/nginx/" root=".."
-            title="nginx">
-
-<title lang="ru">Изменения в nginx</title>
-<title lang="en">nginx changelog</title>
+<change_log title="nginx">
 
 
 <changes ver="1.3.5" date="21.08.2012">