diff --git a/dtd/c3d2web.dtd b/dtd/c3d2web.dtd
index 24f32c026..9486cd695 100644
--- a/dtd/c3d2web.dtd
+++ b/dtd/c3d2web.dtd
@@ -77,6 +77,8 @@
 
 <!ELEMENT em (#PCDATA)>
 
+<!ELEMENT strong (#PCDATA)>
+
 <!ELEMENT dl ((dh)?,(dt|dd)+)>
 <!ATTLIST dl
   class     CDATA   #IMPLIED
@@ -90,6 +92,6 @@
 <!ELEMENT ul ((li)+)>
 <!ELEMENT ol ((li)+)>
 
-<!ELEMENT li (#PCDATA | link | em | image | %Block; )*>
+<!ELEMENT li (#PCDATA | link | em | strong | image | %Block; )*>