diff --git a/mod/assignment/db/mysql.php b/mod/assignment/db/mysql.php
index c6ce006faff..af4615944dc 100644
--- a/mod/assignment/db/mysql.php
+++ b/mod/assignment/db/mysql.php
@@ -117,6 +117,12 @@ function assignment_upgrade($oldversion) {
         table_column('assignment', '', 'emailteachers', 'integer', '2', 'unsigned', 0, 'not null', 'resubmit');
     }
 
+    if ($oldversion < 2005041100) { // replace wiki-like with markdown
+        include_once( "$CFG->dirroot/lib/wiki_to_markdown.php" );
+        $wtm = new WikiToMarkdown();
+        $wtm->update( 'assignment','description','format' );
+    }
+
     return true;
 }
 
diff --git a/mod/assignment/db/postgres7.php b/mod/assignment/db/postgres7.php
index afafaf8201c..859fe890f4c 100644
--- a/mod/assignment/db/postgres7.php
+++ b/mod/assignment/db/postgres7.php
@@ -115,6 +115,12 @@ function assignment_upgrade($oldversion) {
         table_column('assignment', '', 'emailteachers', 'integer', '2', 'unsigned', 0, 'not null', 'resubmit');
     }
 
+    if ($oldversion < 2005041100) { // replace wiki-like with markdown
+        include_once( "$CFG->dirroot/lib/wiki_to_markdown.php" );
+        $wtm = new WikiToMarkdown();
+        $wtm->update( 'assignment','description','format' );
+    }
+
     return true;
 }