diff --git a/README.md b/README.md
index e9bb771..c5245ab 100644
--- a/README.md
+++ b/README.md
@@ -69,9 +69,11 @@ sv2v [OPTIONS] [FILES]
 
 Common flags:
   -e --exclude=CONV         exclude a particular conversion (always,
-                            interface, logic)
+                            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
      --numeric-version      Print just the version number
diff --git a/src/Job.hs b/src/Job.hs
index 46ecff8..53963ca 100644
--- a/src/Job.hs
+++ b/src/Job.hs
@@ -26,11 +26,13 @@ data Job = Job
 defaultJob :: Job
 defaultJob = Job
     { exclude = [] &= typ "CONV"
-        &= help "exclude a particular conversion (always, interface, logic)"
+        &= 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 "compile all files in one compilation unit"
+    , 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")
     }
     &= program "sv2v"
     &= summary "sv2v v0.0.1, (C) 2019 Zachary Snow, 2011-2015 Tom Hawkins"