diff --git a/tools/spec.py b/tools/spec.py
index ca2a1d8..c52a8ae 100644
--- a/tools/spec.py
+++ b/tools/spec.py
@@ -1,9 +1,8 @@
 #!/usr/bin/env python3
-
+import argparse
 import sys
 import logging
 from typing import List, Dict, Set, TextIO
-import pprint
 
 import xml.etree.ElementTree
 
@@ -15,7 +14,7 @@ def rename(name: str):
 
 ###############################################################################
 class Registry:
-    types: Dict[str, object] = {}
+    types: Dict[str, 'Type'] = {}
     extensions: Dict = {}
     features: Dict = {}
     applied: Set = set()
@@ -403,13 +402,13 @@ class Command(Type):
         be the same as self.name for a useful system).
         """
 
-        def __init__(self, name:str, type:str, param:str, depends:List[str]):
+        def __init__(self, name: str, klass: str, param: str, depends: List[str]):
             super().__init__(
                 name=name,
                 depends=depends,
             )
 
-            self.type = type
+            self.type = klass
             self.param = param
 
         def __repr__(self) -> str:
@@ -509,9 +508,9 @@ class Require(object):
 
 # -----------------------------------------------------------------------------
 class Feature(Type):
-    def __init__(self, name: str, requires: List[Require] = []):
+    def __init__(self, name: str, requires: List[Require] = None):
         super().__init__(name)
-        self.requires = requires
+        self.requires = requires or []
 
     def define(self, reg: Registry):
         return "#define %s" % self.name
@@ -569,7 +568,6 @@ class Extension(Type):
 
 ###############################################################################
 def ignore_node(types: Dict[str, Type], root):
-    types, root
     pass
 
 
@@ -595,7 +593,7 @@ def parse_types(reg: Registry, root):
             reg.types[name] = AliasType(name, target)
             continue
 
-        category = t.attrib.get ('category')
+        category = t.attrib.get('category')
 
         # if we don't have a category we should have a bare type that has a
         # dependency on something like a header.
@@ -645,7 +643,8 @@ def parse_enums(reg: Registry, root):
         else:
             owner[valuename] = Constant(node)
 
-#------------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
 def parse_param(root) -> Command.Param:
     assert root.tag == 'param'
 
@@ -657,12 +656,12 @@ def parse_param(root) -> Command.Param:
     param = " ".join(param.split())
 
     name = root.find('name').text
-    type = root.find('type').text
+    klass = root.find('type').text
     depends = [root.find('type').text]
 
     return Command.Param(
         name=name,
-        type=type,
+        klass=klass,
         param=param,
         depends=depends,
     )
@@ -711,7 +710,8 @@ def parse_require(root) -> Require:
 
     return Require(values=values, depends=depends)
 
-##-----------------------------------------------------------------------------
+
+# -----------------------------------------------------------------------------
 def parse_feature(reg: Registry, root):
     assert root.tag == 'feature'
 
@@ -814,7 +814,7 @@ def write_load(dst: TextIO, q: List[Type], reg: Registry):
     """)
 
     for name, test in collections.items():
-        curr = [i for i in commands if     test(i, reg)]
+        curr = [i for i in commands if test(i, reg)]
         next = [i for i in commands if not test(i, reg)]
         commands = next
 
@@ -1016,7 +1016,7 @@ def write_trace(dst: TextIO, q: List[Type], reg: Registry):
 
     for obj in (i for i in q if isinstance(i, Command)):
         inner = ""
-        if obj.name in [ 'vkGetInstanceProcAddr' ]:
+        if obj.name in ['vkGetInstanceProcAddr']:
             inner = """
             
             #define FWD(NAME) \\
@@ -1026,9 +1026,12 @@ def write_trace(dst: TextIO, q: List[Type], reg: Registry):
                 else \\
                     return nullptr;\\
             }
+            #undef FWD
+            
+            #define FWD(NAME) if (!strcmp(#NAME,pName)) { return (PFN_vkVoidFunction)NAME; }
             MAP_INSTANCE_COMMANDS(FWD)
             #undef FWD
-            std::clog << "Missed: " << pName << '\\n';
+            std::clog << "Unhooked: " << pName << '\\n';
             """
 
         dst.write(f"""
@@ -1041,10 +1044,6 @@ def write_trace(dst: TextIO, q: List[Type], reg: Registry):
 
 
 ###############################################################################
-import argparse
-
-
-# -----------------------------------------------------------------------------
 def main():
     logging.getLogger().setLevel(logging.WARNING)