diff --git a/os/sb/user/lib/libdir.c b/os/sb/user/lib/libdir.c
index 8b4d26585..45f9b3ec9 100644
--- a/os/sb/user/lib/libdir.c
+++ b/os/sb/user/lib/libdir.c
@@ -68,7 +68,7 @@ struct dirent *readdir (DIR *dirp) {
       return NULL;
     }
 
-    if (dirp->next >= DIR_BUF_SIZE) {
+    if (dirp->next >= dirp->size) {
       dirp->next = 0;
       continue;
     }