diff --git a/obmc/mapper/server.py b/obmc/mapper/server.py
index 9645f8e..8247568 100644
--- a/obmc/mapper/server.py
+++ b/obmc/mapper/server.py
@@ -717,6 +717,9 @@
         if len(self.defer_signals):
             raise MapperBusyException()
 
+        if not self.cache_get(path):
+            raise MapperNotFoundException(path)
+
         elements = filter(bool, path.split('/'))
         paths = []
         objs = {}