Index: src/org/armedbear/lisp/compile-file.lisp
===================================================================
--- src/org/armedbear/lisp/compile-file.lisp	(revision 11743)
+++ src/org/armedbear/lisp/compile-file.lisp	(working copy)
@@ -41,10 +41,10 @@
 
 (declaim (ftype (function () t) next-classfile-name))
 (defun next-classfile-name ()
-  (let ((name (%format nil "~A-~D"
-                       (substitute #\_ #\. (pathname-name *output-file-pathname*))
+  (let ((name (%format nil "~A_~D"
+                       (substitute #\_ #\- (substitute #\_ #\. (pathname-name *output-file-pathname*)))
                        (incf *class-number*))))
-    (namestring (merge-pathnames (make-pathname :name name :type "cls")
+    (namestring (merge-pathnames (make-pathname :name name :type "class")
                                  *output-file-pathname*))))
 
 (defmacro report-error (&rest forms)
@@ -456,8 +456,8 @@
           (let ((zipfile (concatenate 'string (namestring output-file) ".zip"))
                 (pathnames ()))
             (dotimes (i *class-number*)
-              (let* ((file-namestring (%format nil "~A-~D.cls"
-                                               (substitute #\_ #\. (pathname-name output-file))
+              (let* ((file-namestring (%format nil "~A_~D.class"
+                                               (substitute #\_ #\- (substitute #\_ #\. (pathname-name output-file)))
                                                (1+ i)))
                      (pathname (merge-pathnames file-namestring output-file)))
                 (when (probe-file pathname)