diff --git a/xos/tosca/resources/slice.py b/xos/tosca/resources/slice.py
index 073e205..83062b3 100644
--- a/xos/tosca/resources/slice.py
+++ b/xos/tosca/resources/slice.py
@@ -52,8 +52,8 @@
         self.info("Created Slice '%s' on Site '%s'" % (str(slice), str(slice.site)))
 
     def delete(self, obj):
-        if obj.slivers.exists():
-            self.info("Slice %s has active slivers; skipping delete" % obj.name)
+        if obj.instances.exists():
+            self.info("Slice %s has active instances; skipping delete" % obj.name)
             return
         super(XOSSlice, self).delete(obj)