diff --git a/emuvim/dcemulator/node.py b/emuvim/dcemulator/node.py
index 0d96033..de64d69 100644
--- a/emuvim/dcemulator/node.py
+++ b/emuvim/dcemulator/node.py
@@ -100,7 +100,7 @@
         """
         assert name is not None
         # no duplications
-        if name in self.containers:
+        if name in [c.name for c in self.net.getAllContainers()]:
             raise Exception("Container with name %s already exists." % name)
         # set default parameter
         if image is None: