diff --git a/src/GF/Compile.hs b/src/GF/Compile.hs
index d4b3a9df3..e7e16013c 100644
--- a/src/GF/Compile.hs
+++ b/src/GF/Compile.hs
@@ -76,7 +76,10 @@ optimize opts = cse . suf
 
 buildParser :: Options -> PGF -> PGF
 buildParser opts = 
-    if flag optBuildParser opts then addParsers opts else id
+    case flag optBuildParser opts of
+      BuildParser         -> addParsers opts
+      DontBuildParser     -> id
+      BuildParserOnDemand -> mapConcretes (\cnc -> cnc { cflags = Map.insert (mkCId "parser") "ondemand" (cflags cnc) })
 
 batchCompile :: Options -> [FilePath] -> IOE SourceGrammar
 batchCompile opts files = do
diff --git a/src/GF/Compile/GrammarToGFCC.hs b/src/GF/Compile/GrammarToGFCC.hs
index 3b71bf28a..63491f94e 100644
--- a/src/GF/Compile/GrammarToGFCC.hs
+++ b/src/GF/Compile/GrammarToGFCC.hs
@@ -73,7 +73,7 @@ canon2gfcc opts pars cgr@(M.MGrammar ((a,M.ModMod abm):cms)) =
   cns = map (i2i . fst) cms
   abs = D.Abstr aflags funs cats catfuns
   gflags = Map.empty
-  aflags = Map.fromList [(mkCId f,x) | (f,x) <- moduleOptionsGFO (M.flags abm)]
+  aflags = Map.fromList [(mkCId f,x) | (f,x) <- optionsPGF (M.flags abm)]
   mkDef pty = case pty of
     Yes t -> mkExp t
     _ -> CM.primNotion
@@ -93,7 +93,7 @@ canon2gfcc opts pars cgr@(M.MGrammar ((a,M.ModMod abm):cms)) =
       (lang,D.Concr flags lins opers lincats lindefs printnames params fcfg)
     where
       js = tree2list (M.jments mo)
-      flags   = Map.fromList [(mkCId f,x) | (f,x) <- moduleOptionsGFO (M.flags mo)]
+      flags   = Map.fromList [(mkCId f,x) | (f,x) <- optionsPGF (M.flags mo)]
       opers   = Map.fromAscList [] -- opers will be created as optimization
       utf     = id -- trace (show lang0 +++ show flags) $ 
                 -- if moduleFlag optEncoding (moduleOptions (M.flags mo)) == UTF_8
diff --git a/src/GF/Infra/Option.hs b/src/GF/Infra/Option.hs
index 58e8d4409..25ccb09a2 100644
--- a/src/GF/Infra/Option.hs
+++ b/src/GF/Infra/Option.hs
@@ -5,11 +5,12 @@ module GF.Infra.Option
      Flags(..), 
      Mode(..), Phase(..), Verbosity(..), Encoding(..), OutputFormat(..), 
      SISRFormat(..), Optimization(..), CFGTransform(..), HaskellOption(..),
-     Dump(..), Printer(..), Recomp(..),
+     Dump(..), Printer(..), Recomp(..), BuildParser(..),
      -- * Option parsing 
      parseOptions, parseModuleOptions,
      -- * Option pretty-printing
-     moduleOptionsGFO,
+     optionsGFO,
+     optionsPGF,
      -- * Option manipulation
      addOptions, concatOptions, noOptions,
      modifyFlags,
@@ -136,6 +137,9 @@ data Printer = PrinterStrip -- ^ Remove name qualifiers.
 data Recomp = AlwaysRecomp | RecompIfNewer | NeverRecomp
   deriving (Show,Eq,Ord)
 
+data BuildParser = BuildParser | DontBuildParser | BuildParserOnDemand
+  deriving (Show,Eq,Ord)
+
 data Flags = Flags {
       optMode            :: Mode,
       optStopAfterPhase  :: Phase,
@@ -167,7 +171,7 @@ data Flags = Flags {
       optLexer           :: Maybe String,
       optUnlexer         :: Maybe String,
       optErasing         :: Bool,
-      optBuildParser     :: Bool,
+      optBuildParser     :: BuildParser,
       optWarnings        :: [Warning],
       optDump            :: [Dump]
     }
@@ -195,13 +199,18 @@ parseModuleOptions args = do (opts,nonopts) <- parseOptions args
 
 -- Showing options
 
--- | Pretty-print the module options that are preserved in .gfo files.
-moduleOptionsGFO :: Options -> [(String,String)]
-moduleOptionsGFO opts = 
+-- | Pretty-print the options that are preserved in .gfo files.
+optionsGFO :: Options -> [(String,String)]
+optionsGFO opts = optionsPGF opts
+      ++ [("coding", show (flag optEncoding opts))]
+
+-- | Pretty-print the options that are preserved in .pgf files.
+optionsPGF :: Options -> [(String,String)]
+optionsPGF opts = 
          maybe [] (\x -> [("language",x)]) (flag optSpeechLanguage opts)
       ++ maybe [] (\x -> [("startcat",x)]) (flag optStartCat opts)
-      ++ [("coding", show (flag optEncoding opts))]
       ++ (if flag optErasing opts then [("erasing","on")] else [])
+      ++ (if flag optBuildParser opts == BuildParserOnDemand then [("parser","ondemand")] else [])
 
 -- Option manipulation
 
@@ -256,7 +265,7 @@ defaultFlags = Flags {
       optLexer           = Nothing,
       optUnlexer         = Nothing,
       optErasing         = False,
-      optBuildParser     = True,
+      optBuildParser     = BuildParser,
       optWarnings        = [],
       optDump            = []
     }
@@ -331,7 +340,7 @@ optDescr =
                 ("Character encoding of the source grammar, ENCODING = "
                  ++ concat (intersperse " | " (map fst encodings)) ++ "."),
      Option [] ["erasing"] (onOff erasing False) "Generate erasing grammar (default off).",
-     Option [] ["parser"] (onOff parser True) "Build parser (default on).",
+     Option [] ["parser"] (ReqArg buildParser "VALUE") "Build parser (default on). VALUE = on | off | ondemand",
      Option [] ["startcat"] (ReqArg startcat "CAT") "Grammar start category.",
      Option [] ["language"] (ReqArg language "LANG") "Set the speech language flag to LANG in the generated grammar.",
      Option [] ["lexer"] (ReqArg lexer "LEXER") "Use lexer LEXER.",
@@ -388,7 +397,11 @@ optDescr =
                          Just c  -> set $ \o -> o { optEncoding = c }
                          Nothing -> fail $ "Unknown character encoding: " ++ x
        erasing     x = set $ \o -> o { optErasing = x }
-       parser      x = set $ \o -> o { optBuildParser = x }
+       buildParser x = do v <- case x of
+                                 "on"       -> return BuildParser
+                                 "off"      -> return DontBuildParser
+                                 "ondemand" -> return BuildParserOnDemand
+                          set $ \o -> o { optBuildParser = v }
        startcat    x = set $ \o -> o { optStartCat = Just x }
        language    x = set $ \o -> o { optSpeechLanguage = Just x }
        lexer       x = set $ \o -> o { optLexer = Just x }
diff --git a/src/GF/Source/GrammarToSource.hs b/src/GF/Source/GrammarToSource.hs
index bf3b92222..fa879cf23 100644
--- a/src/GF/Source/GrammarToSource.hs
+++ b/src/GF/Source/GrammarToSource.hs
@@ -133,7 +133,7 @@ trPerh p = case p of
   _ -> P.EMeta ---
 
 trFlags :: Options -> [P.TopDef]
-trFlags = map trFlag . moduleOptionsGFO
+trFlags = map trFlag . optionsGFO
 
 trFlag :: (String,String) -> P.TopDef
 trFlag (f,x) = P.DefFlag [P.FlagDef (tri $ identC (BS.pack f)) (tri $ identC (BS.pack x))]
diff --git a/src/PGF.hs b/src/PGF.hs
index 17f1d8af8..754bcf34f 100644
--- a/src/PGF.hs
+++ b/src/PGF.hs
@@ -214,12 +214,12 @@ readPGF f = do
   g <- parseGrammar s
   return $! addParsers $ toPGF g
 
--- Adds parsers for all concretes that don't have a parser.
+-- Adds parsers for all concretes that don't have a parser and that have parser=ondemand.
 addParsers :: PGF -> PGF
-addParsers pgf = pgf { concretes = Map.map conv (concretes pgf) }
-  where
-    conv cnc | isJust (parser cnc) = cnc
-             | otherwise = cnc { parser = Just (PMCFG.convertConcrete (abstract pgf) cnc) }
+addParsers pgf = mapConcretes (\cnc -> if wantsParser cnc then addParser cnc else cnc) pgf
+    where
+      wantsParser cnc = isNothing (parser cnc) && Map.lookup (mkCId "parser") (cflags cnc) == Just "ondemand"
+      addParser cnc = cnc { parser = Just (PMCFG.convertConcrete (abstract pgf) cnc) }
 
 linearize pgf lang = concat . take 1 . PGF.Linearize.linearizes pgf lang