diff --git a/compiler/ir1opt.lisp b/compiler/ir1opt.lisp
index 8b09890bac0d28d2a4cc1b504bd8e3a474c94214..592ae72ca742095e7ed120f66496bb2caf2064d8 100644
--- a/compiler/ir1opt.lisp
+++ b/compiler/ir1opt.lisp
@@ -134,7 +134,7 @@
 ;;;    Return the derived type for Cont's first value.  This is guaranteed not
 ;;; to be a Values or Function type.
 ;;;
-(proclaim '(function continuation-type (continuation) type))
+(proclaim '(function continuation-type (continuation) ctype))
 (defun continuation-type (cont)
   (single-value-type (continuation-derived-type cont)))