diff --git a/Data/Aeson/AutoType/Format.hs b/Data/Aeson/AutoType/Format.hs
--- a/Data/Aeson/AutoType/Format.hs
+++ b/Data/Aeson/AutoType/Format.hs
@@ -65,9 +65,10 @@
     header = Text.concat ["data ", identifier, " = ", identifier, " { "]
 
 -- | Explanatory type alias for making declarations
--- First element of the pair is original JSON identifier,
--- second element of the pair is the mapped identifier name in Haskell.
-type MappedKey = (Text, Text)
+-- First element of the triple is original JSON identifier,
+-- second element of the triple is the mapped identifier name in Haskell.
+-- third element of the triple shows the type in a formatted way
+type MappedKey = (Text, Text, Text)
 
 -- | Make ToJSON declaration, given identifier (object name in Haskell) and mapping of its keys
 -- from JSON to Haskell identifiers *in the same order* as in *data type declaration*.
@@ -81,8 +82,9 @@
     makeParser identifier [] = Text.unwords ["return ", identifier]
     makeParser identifier _  = Text.unwords [identifier, "<$>", inner]
     inner                    = " <*> " `Text.intercalate`
-                                  map (takeValue . fst) contents
-    takeValue jsonId = Text.concat ["v .: \"", jsonId, "\""]
+                                  map takeValue contents
+    takeValue (jsonId, _, ty) | isNullable ty  = Text.concat ["v .:? \"", jsonId, "\""]
+    takeValue (jsonId, _, _ )                  = Text.concat ["v .:  \"", jsonId, "\""]
 -- Contents example for wrapFromJSON:
 -- " <$>
 --"                           v .: "hexValue"  <*>
@@ -101,7 +103,7 @@
              | otherwise            = ".."
     inner = ", " `Text.intercalate`
               map putValue contents
-    putValue (jsonId, haskellId) = Text.unwords [escapeText jsonId, ".=", haskellId]
+    putValue (jsonId, haskellId, _typeText) = Text.unwords [escapeText jsonId, ".=", haskellId]
     escapeText = Text.pack . show . Text.unpack
 -- Contents example for wrapToJSON
 --"hexValue"  .= hexValue
@@ -119,12 +121,11 @@
 newDecl identifier kvs = do attrs <- forM kvs $ \(k, v) -> do
                               formatted <- formatType v
                               return (k, normalizeFieldName identifier k, formatted)
-                            let fieldMapping = map (\(jn, hn, _) -> (jn, hn)) attrs
                             let decl = Text.unlines [wrapDecl     identifier $ fieldDecls attrs
                                                     ,""
-                                                    ,makeFromJSON identifier fieldMapping
+                                                    ,makeFromJSON identifier attrs
                                                     ,""
-                                                    ,makeToJSON   identifier fieldMapping]
+                                                    ,makeToJSON   identifier attrs]
                             addDecl decl
                             return identifier
   where
@@ -133,6 +134,9 @@
     fieldDecl (_jsonName, haskellName, fType) = Text.concat [
                                                   "    ", haskellName, " :: ", fType]
 
+-- | Whether the type is nullable or in other words - represented by Maybe type.
+isNullable = ("Maybe" `Text.isPrefixOf`)
+
 addDecl decl = decls %%= (\ds -> ((), decl:ds))
 
 -- | Add new type alias for Array type
@@ -168,6 +172,7 @@
 formatType (TUnion u) | uu <- u `Set.difference` emptySetLikes,
                         Set.size uu == 1     = do fmt <- formatType $ head $ Set.toList uu
                                                   return $ "Maybe " `Text.append` fmt
+-- TODO: Use Maybe (...) when nullable?
 formatType (TUnion u)                        = do tys <- forM (Set.toList u) formatType
                                                   return $ mkUnion tys
   where
diff --git a/Data/Aeson/AutoType/Test.hs b/Data/Aeson/AutoType/Test.hs
--- a/Data/Aeson/AutoType/Test.hs
+++ b/Data/Aeson/AutoType/Test.hs
@@ -4,7 +4,7 @@
     arbitraryTopValue
   ) where
 
-import           Data.Functor                        ((<$>))
+import           Control.Applicative                 ((<$>), (<*>))
 import           Data.Aeson
 import           Data.Function                       (on)
 import           Data.Generics.Uniplate.Data
diff --git a/GenerateTestJSON.hs b/GenerateTestJSON.hs
--- a/GenerateTestJSON.hs
+++ b/GenerateTestJSON.hs
@@ -38,20 +38,18 @@
 import           Data.Aeson.AutoType.Test
 import           HFlags
 
-fst3 ::  (t, t1, t2) -> t
-fst3 (a, _, _) = a
-
 -- * Command line flags
 defineFlag "z:size"            (10     :: Int)        "Size of generated elements"
 defineFlag "s:stem"            ("Test" :: FilePath)   "Test filename stem"
 defineFlag "c:count"           (100    :: Int)        "Number of test cases to generate."
-defineFlag "o:outputFilename"   defaultOutputFilename "Write output to the given file"
-defineFlag "suggest"            True                  "Suggest candidates for unification"
+--defineFlag "o:outputFilename"   defaultOutputFilename "Write output to the given file"
+flags_suggest = True
+--defineFlag "suggest"            True                  "Suggest candidates for unification"
 defineFlag "autounify"          True                  "Automatically unify suggested candidates"
-defineFlag "t:test"             False                 "Try to run generated parser after"
+defineFlag "t:test"             True                  "Try to run generated parser after"
 defineFlag "d:debug"            False                 "Set this flag to see more debugging info"
 defineFlag "keep"               False                 "Keep also the successful tests"
-defineFlag "fakeFlag"           True                  "Ignore this flag - it doesn't exist!!! It is workaround to library problem."
+defineFlag "fakeFlag"           True                  "Ignore this flag - it doesn't exist!!! It is workaround for a library problem."
 
 -- Tracing is switched off:
 myTrace :: String -> IO ()
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,10 @@
 Changelog
 =========
+    0.2.5.13  Apr 2015
+
+        * Correctly handling lone option, not yet union with optionality.
+          Fixed: #3.
+
     0.2.5.12  Apr 2015
 
         * Added typechecking before and after type unification.
diff --git a/json-autotype.cabal b/json-autotype.cabal
--- a/json-autotype.cabal
+++ b/json-autotype.cabal
@@ -1,6 +1,6 @@
 -- Build information for the package.
 name:                json-autotype
-version:             0.2.5.12
+version:             0.2.5.13
 synopsis:            Automatic type declaration for JSON input data
 description:         Generates datatype declarations with Aeson's "FromJSON" instances
                      from a set of example ".json" files.