diff --git a/src/components/input.lisp b/src/components/input.lisp
index fed0e14..c25c125 100644
--- a/src/components/input.lisp
+++ b/src/components/input.lisp
@@ -224,6 +224,7 @@ Returns a mouse-event struct."
 
 #+sbcl
 (eval-when (:load-toplevel :execute)
+  (require :sb-posix)
   (sb-sys:enable-interrupt sb-posix:sigwinch
     (lambda (signal info context)
       (declare (ignore signal info context))