diff --git a/asdf.lisp b/asdf.lisp
index 61bf3cfae117249c2a0a8d74ae633f3c7ca31fcd..7edbada4ad308cda3672e0eeec03c440116472b2 100644
--- a/asdf.lisp
+++ b/asdf.lisp
@@ -1140,9 +1140,10 @@ to `~a` which is not a directory.~@:>"
                                        (equalp (missing-requires c)
                                                required-c))))
 |#
-                        (and (typep c 'missing-dependency)
-                             (equalp (missing-requires c)
-                                     required-c)))))))
+                        (or (null c)
+                            (and (typep c 'missing-dependency)
+                                 (equalp (missing-requires c)
+                                         required-c))))))))
              (do-dep (op dep)
                (cond ((eq op 'feature)
                       (or (member (car dep) *features*)