diff --git a/src/main/org/freemarker/docgen/Transform.java b/src/main/org/freemarker/docgen/Transform.java
index e58ada9..b1d771b 100644
--- a/src/main/org/freemarker/docgen/Transform.java
+++ b/src/main/org/freemarker/docgen/Transform.java
@@ -973,7 +973,7 @@
             throw new BugException(e);
         }
 
-        fmConfig = new Configuration(Configuration.VERSION_2_3_21);
+        fmConfig = new Configuration(Configuration.VERSION_2_3_23);
 
         TemplateLoader templateLoader = new ClassTemplateLoader(
                 Transform.class, "templates");