diff --git a/cocluto/PowerDiagram.py b/cocluto/PowerDiagram.py
index 6999e40..8dfcabb 100644
--- a/cocluto/PowerDiagram.py
+++ b/cocluto/PowerDiagram.py
@@ -52,7 +52,7 @@ class Machine(object):
     def get_max_amperes(self):
         capacity = None
         if len(self.input_plugs) > 0:
-            capacity = self.input_plugs.values()[0].get_max_amperes()
+            capacity = list(self.input_plugs.values())[0].get_max_amperes()
             capacity = add_capacity_constraints(capacity, self.current_capacity_constraint)
         return capacity
 
@@ -189,7 +189,7 @@ class Connection(object):
         from_machine = self.from_plug.machine
         if from_machine.is_power_provider():
             return from_machine
-        input_plug_names = from_machine.input_plugs.keys()
+        input_plug_names = list(from_machine.input_plugs.keys())
         assert len(input_plug_names) == 1, "from_machine is supposed to be a power strip (which is expected to only have one input)"
         input_plug = from_machine.input_plugs[input_plug_names[0]]
         return input_plug.get_incoming_connection().get_power_provider()