diff --git a/lisp/ob-mscgen.el b/lisp/ob-mscgen.el
index b5a019b8f..500ff96a2 100644
--- a/lisp/ob-mscgen.el
+++ b/lisp/ob-mscgen.el
@@ -62,9 +62,6 @@
   '((:results . "file") (:exports . "results"))
   "Default arguments to use when evaluating a mscgen source block.")
 
-(defun org-babel-expand-body:mscgen (body params)
-  "Expand BODY according to PARAMS, return the expanded body." body)
-
 (defun org-babel-execute:mscgen (body params)
   "Execute a block of Mscgen code with Babel.
 This function is called by `org-babel-execute-src-block'.