diff --git a/README.md b/README.md
index c5245ab..2b7dd2e 100644
--- a/README.md
+++ b/README.md
@@ -67,15 +67,18 @@ Below is the current usage printout. This interface is subject to change.
 ```
 sv2v [OPTIONS] [FILES]
 
-Common flags:
-  -e --exclude=CONV         exclude a particular conversion (always,
+Preprocessing:
+  -I --incdir=DIR           Add directory to include search path
+  -D --define=NAME[=VALUE]  Define a macro for preprocessing
+     --siloed               Lex input files separately, so macros from
+                            earlier files are not defined in later files
+Conversion:
+  -E --exclude=CONV         Exclude a particular conversion (always,
                             interface, or logic)
-  -i --incdir=DIR           add directory to include search path
-  -d --define=NAME[=VALUE]  define a macro for preprocessing
-  -o --oneunit              put all files in one compilation unit, so macros
-                            from earlier files remain defined in later files
-  -? --help                 Display help message
-  -V --version              Print version information
+  -v --verbose              Retain certain conversion artifacts
+Other:
+     --help                 Display help message
+     --version              Print version information
      --numeric-version      Print just the version number
 ```
 
diff --git a/src/Job.hs b/src/Job.hs
index 804921f..0633df5 100644
--- a/src/Job.hs
+++ b/src/Job.hs
@@ -7,7 +7,9 @@
 
 module Job where
 
+import System.IO (stderr, hPutStr)
 import System.Console.CmdArgs
+import System.Environment (getArgs, withArgs)
 
 data Exclude
     = Always
@@ -17,34 +19,84 @@ data Exclude
     deriving (Show, Typeable, Data, Eq)
 
 data Job = Job
-    { exclude :: [Exclude]
-    , files :: [FilePath]
+    { files :: [FilePath]
     , incdir :: [FilePath]
     , define :: [String]
-    , oneunit :: Bool
+    , siloed :: Bool
+    , exclude :: [Exclude]
     , verbose :: Bool
     } deriving (Show, Typeable, Data)
 
 defaultJob :: Job
 defaultJob = Job
-    { exclude = [] &= typ "CONV"
-        &= help "exclude a particular conversion (always, interface, or logic)"
-    , files = def &= args &= typ "FILES"
-    , incdir = def &= typDir &= help "add directory to include search path"
-    , define = def &= typ "NAME[=VALUE]" &= help ("define a macro for"
-        ++ " preprocessing")
-    , oneunit = False &= help ("put all files in one compilation unit, so"
-        ++ " macros from earlier files remain defined in later files")
-    , verbose = False &= help "retain certain conversion artifacts"
+    { files = def &= args &= typ "FILES"
+    , incdir = nam_ "I" &= name "incdir" &= typDir
+        &= help "Add directory to include search path"
+        &= groupname "Preprocessing"
+    , define = nam_ "D" &= name "define" &= typ "NAME[=VALUE]"
+        &= help "Define a macro for preprocessing"
+    , siloed = nam_ "siloed" &= help ("Lex input files separately, so"
+        ++ " macros from earlier files are not defined in later files")
+    , exclude = nam_ "exclude" &= name "E" &= typ "CONV"
+        &= help "Exclude a particular conversion (always, interface, or logic)"
+        &= groupname "Conversion"
+    , verbose = nam "verbose" &= help "Retain certain conversion artifacts"
     }
     &= program "sv2v"
     &= summary "sv2v v0.0.1, (C) 2019 Zachary Snow, 2011-2015 Tom Hawkins"
     &= details [ "sv2v converts SystemVerilog to Verilog."
                , "More info: https://github.com/zachjs/sv2v" ]
+    &= helpArg [explicit, name "help", groupname "Other"]
+    &= versionArg [explicit, name "version"]
+    &= verbosityArgs [ignore] [ignore]
+    where
+        -- borrowed from: https://github.com/ndmitchell/hlint
+        nam xs = nam_ xs &= name [head xs]
+        nam_ xs = def &= name xs &= explicit
+
+type DeprecationPhase = [String] -> IO [String]
+
+oneunit :: DeprecationPhase
+oneunit strs = do
+    let strs' = filter (not . isOneunitArg) strs
+    if strs == strs'
+        then return strs
+        else do
+            hPutStr stderr $ "Deprecation warning: --oneunit has been removed, "
+                ++ "and is now on by default\n"
+            return strs'
+    where
+        isOneunitArg :: String -> Bool
+        isOneunitArg "-o" = True
+        isOneunitArg "--oneunit" = True
+        isOneunitArg _ = False
+
+flagRename :: String -> String -> DeprecationPhase
+flagRename before after strs = do
+    let strs' = map rename strs
+    if strs == strs'
+        then return strs
+        else do
+            hPutStr stderr $ "Deprecation warning: " ++ before ++
+                " has been renamed to " ++ after ++ "\n"
+            return strs'
+    where
+        rename :: String -> String
+        rename arg =
+            if before == take (length before) arg
+                then after ++ drop (length before) arg
+                else arg
 
 readJob :: IO Job
 readJob = do
-    job <- cmdArgs defaultJob
+    strs <- getArgs
+    strs' <- oneunit strs
+        >>= flagRename "-i" "-I"
+        >>= flagRename "-d" "-D"
+        >>= flagRename "-e" "-E"
+        >>= flagRename "-V" "--version"
+        >>= flagRename "-?" "--help"
+    job <- withArgs (strs') $ cmdArgs defaultJob
     return $ if verbose job
         then job { exclude = Succinct : exclude job }
         else job
diff --git a/src/sv2v.hs b/src/sv2v.hs
index 7d0a51b..891b049 100644
--- a/src/sv2v.hs
+++ b/src/sv2v.hs
@@ -8,7 +8,7 @@ import System.IO
 import System.Exit
 
 import Data.List (elemIndex)
-import Job (readJob, files, exclude, incdir, define, oneunit)
+import Job (readJob, files, exclude, incdir, define, siloed)
 import Convert (convert)
 import Language.SystemVerilog.Parser (parseFiles)
 
@@ -25,7 +25,7 @@ main = do
     let includePaths = incdir job
     let defines = map splitDefine $ define job
     let singleton = \x -> [x]
-    let toFileLists = if oneunit job then singleton else map singleton
+    let toFileLists = if siloed job then map singleton else singleton
     astLists <- mapM
         (parseFiles includePaths defines)
         (toFileLists $ files job)