diff --git a/command.py b/command.py
index a941b95..8e93787 100644
--- a/command.py
+++ b/command.py
@@ -74,7 +74,7 @@
         project = all.get(arg)
 
         if not project:
-          path = os.path.abspath(arg)
+          path = os.path.abspath(arg).replace('\\', '/')
 
           if not by_path:
             by_path = dict()
@@ -82,13 +82,15 @@
               by_path[p.worktree] = p
 
           if os.path.exists(path):
+            oldpath = None
             while path \
-              and path != '/' \
+              and path != oldpath \
               and path != self.manifest.topdir:
               try:
                 project = by_path[path]
                 break
               except KeyError:
+                oldpath = path
                 path = os.path.dirname(path)
           else:
             try: