Index: source/Interpreter/CommandInterpreter.cpp
===================================================================
--- source/Interpreter/CommandInterpreter.cpp
+++ source/Interpreter/CommandInterpreter.cpp
@@ -337,6 +337,8 @@
         AddAlias ("image", cmd_obj_sp);
 
 
+    alias_arguments_vector_sp.reset(new OptionArgVector);
+
     cmd_obj_sp = GetCommandSPExact ("expression", false);
     if (cmd_obj_sp)
     {