diff --git a/foreign/c/pointer.scm b/foreign/c/pointer.scm
index 0fed821..a23c805 100644
--- a/foreign/c/pointer.scm
+++ b/foreign/c/pointer.scm
@@ -104,7 +104,8 @@
   (gauche (define c-null? pointer-null?))
   (stklos (define c-null?
             (lambda (pointer)
-              (and pointer
+              (and (not (void? pointer))
+                   pointer
                    (cpointer-null? pointer)))))
   (else (define c-null?
           (lambda (pointer)