diff --git a/src/Convert/SizeCast.hs b/src/Convert/SizeCast.hs
index b5566de..a4457df 100644
--- a/src/Convert/SizeCast.hs
+++ b/src/Convert/SizeCast.hs
@@ -73,7 +73,7 @@ traverseExprM =
 castFn :: Expr -> Signing -> Description
 castFn e sg =
     PackageItem $
-    Function (Just Automatic) t fnName [decl] [Return $ Ident inp]
+    Function Automatic t fnName [decl] [Return $ Ident inp]
     where
         inp = "inp"
         r = (simplify $ BinOp Sub e (Number "1"), Number "0")
diff --git a/src/Convert/Struct.hs b/src/Convert/Struct.hs
index 08bba5f..661d76d 100644
--- a/src/Convert/Struct.hs
+++ b/src/Convert/Struct.hs
@@ -211,7 +211,7 @@ traverseDeclM structs origDecl = do
 packerFn :: TypeFunc -> ModuleItem
 packerFn structTf =
     MIPackageItem $
-    Function Nothing (structTf []) fnName decls [retStmt]
+    Function Automatic (structTf []) fnName decls [retStmt]
     where
         Struct _ fields [] = structTf []
         toInput (t, x) = Variable Input t x [] Nothing
diff --git a/src/Convert/Traverse.hs b/src/Convert/Traverse.hs
index f348570..b6d0235 100644
--- a/src/Convert/Traverse.hs
+++ b/src/Convert/Traverse.hs
@@ -153,9 +153,9 @@ traverseModuleItemsM mapper (Part attrs extern kw lifetime name ports items) = d
 traverseModuleItemsM mapper (PackageItem packageItem) = do
     let item = MIPackageItem packageItem
     converted <-
-        traverseModuleItemsM mapper (Part [] False Module Nothing "DNE" [] [item])
+        traverseModuleItemsM mapper (Part [] False Module Inherit "DNE" [] [item])
     let item' = case converted of
-            Part [] False Module Nothing "DNE" [] [newItem] -> newItem
+            Part [] False Module Inherit "DNE" [] [newItem] -> newItem
             _ -> error $ "redirected PackageItem traverse failed: "
                     ++ show converted
     return $ case item' of
@@ -164,9 +164,9 @@ traverseModuleItemsM mapper (PackageItem packageItem) = do
 traverseModuleItemsM mapper (Package lifetime name packageItems) = do
     let items = map MIPackageItem packageItems
     converted <-
-        traverseModuleItemsM mapper (Part [] False Module Nothing "DNE" [] items)
+        traverseModuleItemsM mapper (Part [] False Module Inherit "DNE" [] items)
     let items' = case converted of
-            Part [] False Module Nothing "DNE" [] newItems -> newItems
+            Part [] False Module Inherit "DNE" [] newItems -> newItems
             _ -> error $ "redirected Package traverse failed: "
                     ++ show converted
     return $ Package lifetime name $ map (\(MIPackageItem item) -> item) items'
@@ -1017,9 +1017,9 @@ collectStmtAsgnsM = collectify traverseStmtAsgnsM
 traverseNestedModuleItemsM :: Monad m => MapperM m ModuleItem -> MapperM m ModuleItem
 traverseNestedModuleItemsM mapper item = do
     converted <-
-        traverseModuleItemsM mapper (Part [] False Module Nothing "DNE" [] [item])
+        traverseModuleItemsM mapper (Part [] False Module Inherit "DNE" [] [item])
     let items' = case converted of
-            Part [] False Module Nothing "DNE" [] newItems -> newItems
+            Part [] False Module Inherit "DNE" [] newItems -> newItems
             _ -> error $ "redirected NestedModuleItems traverse failed: "
                     ++ show converted
     return $ case items' of
diff --git a/src/Language/SystemVerilog/AST/Description.hs b/src/Language/SystemVerilog/AST/Description.hs
index e0d4458..2ce162b 100644
--- a/src/Language/SystemVerilog/AST/Description.hs
+++ b/src/Language/SystemVerilog/AST/Description.hs
@@ -25,9 +25,9 @@ import Language.SystemVerilog.AST.Type (Type, Identifier)
 import {-# SOURCE #-} Language.SystemVerilog.AST.ModuleItem (ModuleItem)
 
 data Description
-    = Part [Attr] Bool PartKW (Maybe Lifetime) Identifier [Identifier] [ModuleItem]
+    = Part [Attr] Bool PartKW Lifetime Identifier [Identifier] [ModuleItem]
     | PackageItem PackageItem
-    | Package (Maybe Lifetime) Identifier [PackageItem]
+    | Package Lifetime Identifier [PackageItem]
     deriving Eq
 
 instance Show Description where
@@ -35,12 +35,12 @@ instance Show Description where
     show (Part attrs True  kw lifetime name _ items) =
         printf "%sextern %s %s%s %s;"
             (concatMap showPad attrs)
-            (show kw) (showLifetime lifetime) name (indentedParenList itemStrs)
+            (show kw) (showPad lifetime) name (indentedParenList itemStrs)
         where itemStrs = map (init . show) items
     show (Part attrs False kw lifetime name ports items) =
         printf "%s%s %s%s%s;\n%s\nend%s"
             (concatMap showPad attrs)
-            (show kw) (showLifetime lifetime) name portsStr bodyStr (show kw)
+            (show kw) (showPad lifetime) name portsStr bodyStr (show kw)
         where
             portsStr = if null ports
                 then ""
@@ -48,15 +48,15 @@ instance Show Description where
             bodyStr = indent $ unlines' $ map show items
     show (Package lifetime name items) =
         printf "package %s%s;\n%s\nendpackage"
-            (showLifetime lifetime) name bodyStr
+            (showPad lifetime) name bodyStr
         where
             bodyStr = indent $ unlines' $ map show items
     show (PackageItem i) = show i
 
 data PackageItem
     = Typedef Type Identifier
-    | Function (Maybe Lifetime) Type Identifier [Decl] [Stmt]
-    | Task     (Maybe Lifetime)      Identifier [Decl] [Stmt]
+    | Function Lifetime Type Identifier [Decl] [Stmt]
+    | Task     Lifetime      Identifier [Decl] [Stmt]
     | Import Identifier (Maybe Identifier)
     | Export (Maybe (Identifier, Maybe Identifier))
     | Decl Decl
@@ -68,11 +68,11 @@ instance Show PackageItem where
     show (Typedef t x) = printf "typedef %s %s;" (show t) x
     show (Function ml t x i b) =
         printf "function %s%s%s;\n%s\n%s\nendfunction"
-            (showLifetime ml) (showPad t) x (indent $ show i)
+            (showPad ml) (showPad t) x (indent $ show i)
             (indent $ unlines' $ map show b)
     show (Task ml x i b) =
         printf "task %s%s;\n%s\n%s\nendtask"
-            (showLifetime ml) x (indent $ show i)
+            (showPad ml) x (indent $ show i)
             (indent $ unlines' $ map show b)
     show (Import x y) = printf "import %s::%s;" x (fromMaybe "*" y)
     show (Export Nothing) = "export *::*";
@@ -96,12 +96,10 @@ instance Show PartKW where
 data Lifetime
     = Static
     | Automatic
+    | Inherit
     deriving (Eq, Ord)
 
 instance Show Lifetime where
     show Static    = "static"
     show Automatic = "automatic"
-
-showLifetime :: Maybe Lifetime -> String
-showLifetime Nothing = ""
-showLifetime (Just l) = show l ++ " "
+    show Inherit   = ""
diff --git a/src/Language/SystemVerilog/Parser/Parse.y b/src/Language/SystemVerilog/Parser/Parse.y
index b50e0cd..f924e9b 100644
--- a/src/Language/SystemVerilog/Parser/Parse.y
+++ b/src/Language/SystemVerilog/Parser/Parse.y
@@ -513,7 +513,7 @@ Part(begin, end) :: { Description }
   | AttributeInstances "extern" begin PartHeader                          { $4 $1 True  $3 [] }
 
 PartHeader :: { [Attr] -> Bool -> PartKW -> [ModuleItem] -> Description }
-  : opt(Lifetime) Identifier PackageImportDeclarations Params PortDecls ";" { \attrs extern kw items -> Part attrs extern kw $1 $2 (fst $5) ($3 ++ $4 ++ (snd $5) ++ items) }
+  : Lifetime Identifier PackageImportDeclarations Params PortDecls ";" { \attrs extern kw items -> Part attrs extern kw $1 $2 (fst $5) ($3 ++ $4 ++ (snd $5) ++ items) }
 
 ModuleKW :: { PartKW }
   : "module" { Module }
@@ -521,7 +521,7 @@ InterfaceKW :: { PartKW }
   : "interface" { Interface }
 
 PackageDeclaration :: { Description }
-  : "package" opt(Lifetime) Identifier ";" PackageItems "endpackage" opt(Tag) { Package $2 $3 $5 }
+  : "package" Lifetime Identifier ";" PackageItems "endpackage" opt(Tag) { Package $2 $3 $5 }
 
 Tag :: { Identifier }
   : ":" Identifier { $2 }
@@ -613,7 +613,7 @@ DeclOrStmtToken :: { DeclToken }
   | "." Identifier { DTDot      $2 }
   | PortBindings   { DTInstance $1 }
   | Signing        { DTSigning  $1 }
-  | Lifetime       { DTLifetime $1 }
+  | ExplicitLifetime { DTLifetime $1 }
   | Identifier "::" Identifier { DTPSIdent $1 $3 }
   | "const" PartialType { DTType $2 }
   | "{" StreamOp StreamSize Concat "}" { DTStream $2 $3           (map toLHS $4) }
@@ -775,9 +775,9 @@ PackageItem :: { [PackageItem] }
   | NonDeclPackageItem { $1 }
 NonDeclPackageItem :: { [PackageItem] }
   : "typedef" Type Identifier ";" { [Typedef $2 $3] }
-  | "function" opt(Lifetime) FuncRetAndName    TFItems DeclsAndStmts "endfunction" opt(Tag) { [Function $2 (fst $3) (snd $3) (map defaultFuncInput $ (map makeInput $4) ++ fst $5) (snd $5)] }
-  | "function" opt(Lifetime) "void" Identifier TFItems DeclsAndStmts "endfunction" opt(Tag) { [Task     $2 $4                (map defaultFuncInput $ $5 ++ fst $6) (snd $6)] }
-  | "task"     opt(Lifetime) Identifier        TFItems DeclsAndStmts "endtask"     opt(Tag) { [Task     $2 $3                (map defaultFuncInput $ $4 ++ fst $5) (snd $5)] }
+  | "function" Lifetime FuncRetAndName    TFItems DeclsAndStmts "endfunction" opt(Tag) { [Function $2 (fst $3) (snd $3) (map defaultFuncInput $ (map makeInput $4) ++ fst $5) (snd $5)] }
+  | "function" Lifetime "void" Identifier TFItems DeclsAndStmts "endfunction" opt(Tag) { [Task     $2 $4                (map defaultFuncInput $ $5 ++ fst $6) (snd $6)] }
+  | "task"     Lifetime Identifier        TFItems DeclsAndStmts "endtask"     opt(Tag) { [Task     $2 $3                (map defaultFuncInput $ $4 ++ fst $5) (snd $5)] }
   | "import" PackageImportItems ";" { map (uncurry Import) $2 }
   | "export" PackageImportItems ";" { map (Export .  Just) $2 }
   | "export" "*" "::" "*" ";"       { [Export Nothing] } -- "Nothing" being no restrictions
@@ -818,6 +818,9 @@ AlwaysKW :: { AlwaysKW }
   | "always_latch" { AlwaysLatch }
 
 Lifetime :: { Lifetime }
+  : {- empty -} { Inherit }
+  | ExplicitLifetime { $1 }
+ExplicitLifetime :: { Lifetime }
   : "static"    { Static    }
   | "automatic" { Automatic }