diff --git a/src/iframe.coffee b/src/iframe.coffee
index 694d9e5..051ac9b 100644
--- a/src/iframe.coffee
+++ b/src/iframe.coffee
@@ -19,7 +19,7 @@ class IframeRuntime extends Base
       @graph.removeListener 'changeProperties', @updateIframe
 
     # Update contents on property changes
-    graph.on 'changeProperties', @updateIframe
+    graph.on 'changeProperties', @updateIframe if graph
 
     # Ensure iframe gets updated
     do @updateIframe
diff --git a/src/microflo.coffee b/src/microflo.coffee
index 5e10437..8c8a7ed 100644
--- a/src/microflo.coffee
+++ b/src/microflo.coffee
@@ -65,7 +65,7 @@ class MicroFloRuntime extends Base
       @graph.removeListener 'changeProperties', @updatecontainer
 
     # Update contents on property changes
-    graph.on 'changeProperties', @updatecontainer
+    graph.on 'changeProperties', @updatecontainer if graph
     super graph
 
   openComm: () ->