diff --git a/src/mcedit2/plugins/command.py b/src/mcedit2/plugins/command.py
index b04e0d2..790d4ee 100644
--- a/src/mcedit2/plugins/command.py
+++ b/src/mcedit2/plugins/command.py
@@ -89,9 +89,11 @@ class SimpleCommandPlugin(CommandPlugin):
         if result == QtGui.QDialog.Accepted:
             command = SimpleRevisionCommand(self.editorSession, self.displayName)
             with self.editorSession.beginCommand(command):
-                self.perform(self.editorSession.worldEditor, dialog.getOptions())
+                self.perform(self.editorSession.currentDimension,
+                             self.editorSession.currentSelection,
+                             dialog.getOptions())
 
-    def perform(self, world, options):
+    def perform(self, dimension, selection, options):
         raise NotImplementedError
 
 
diff --git a/src/plugins/simple_options.py b/src/plugins/simple_options.py
index c7d9cbd..fc0eab3 100644
--- a/src/plugins/simple_options.py
+++ b/src/plugins/simple_options.py
@@ -90,7 +90,7 @@ class SimpleOptionsDemo(SimpleCommandPlugin):
         }
     ]
 
-    def perform(self, world, options):
+    def perform(self, dimension, selection, options):
         lines = []
         for key in [
             'myIntOption',