diff --git a/src/cmp/proclamations.lsp b/src/cmp/proclamations.lsp
index 2fd567cd1..ce51c7342 100644
--- a/src/cmp/proclamations.lsp
+++ b/src/cmp/proclamations.lsp
@@ -188,7 +188,7 @@
 
 ;; ECL extensions:
 (proclamation si:specialp (symbol) gen-bool :predicate)
-(proclamation si::do-defsetf (symbol function) t)
+(proclamation si::do-defsetf (symbol (or symbol function)) t)
 (proclamation si::do-define-setf-method (symbol function) t)
 
 ;;;