diff --git a/src/GF/Shell/HelpFile.hs b/src/GF/Shell/HelpFile.hs
index 9a4daa282..e989d5104 100644
--- a/src/GF/Shell/HelpFile.hs
+++ b/src/GF/Shell/HelpFile.hs
@@ -349,13 +349,16 @@ txtHelpFile =
   "\n      the tree." ++
   "\n  options:" ++
   "\n      -metas    also return trees that include metavariables" ++
+  "\n      -all      generate all (lazily)" ++
+  "\n      -lin      linearize result of -all (otherwise, use pipe to linearize)" ++
   "\n  flags:" ++
   "\n      -depth    generate to this depth (default 3)" ++
   "\n      -atoms    take this number of atomic rules of each category (default unlimited)" ++
   "\n      -alts     take this number of alternatives at each branch (default unlimited)" ++
   "\n      -cat      generate in this category" ++
+  "\n      -old      use an older algorithm (usually more memory-consuming)" ++
   "\n      -lang     use the abstract syntax of this grammar" ++
-  "\n      -number   generate (at most) this number of trees" ++
+  "\n      -number   generate (at most) this number of trees (also works with -all)" ++
   "\n      -noexpand don't expand these categories (comma-separated, e.g. -noexpand=V,CN)" ++
   "\n      -doexpand only expand these categories (comma-separated, e.g. -doexpand=V,CN)" ++
   "\n  examples:" ++
diff --git a/src/GF/UseGrammar/Generate.hs b/src/GF/UseGrammar/Generate.hs
index d0697b8dd..25e27df1c 100644
--- a/src/GF/UseGrammar/Generate.hs
+++ b/src/GF/UseGrammar/Generate.hs
@@ -50,8 +50,9 @@ generateTrees opts gr cat n mn mt = map str2tr $ generate gr' ifm cat' n mn mt'
     ifm  = oElem showOld opts
 
 generateAll :: Options -> (Exp -> IO ()) -> GFCGrammar -> Cat -> IO ()
-generateAll opts io gr cat = mapM_ (io . str2tr) $ gen cat'
+generateAll opts io gr cat = mapM_ (io . str2tr) $ num $ gen cat'
   where
+    num  = optIntOrAll opts flagNumber
     gr'  = gr2sgr opts emptyProbs gr
     cat' = prt $ snd cat
     gen c = generate gr' False c 10 Nothing Nothing
diff --git a/src/HelpFile b/src/HelpFile
index baf2bf761..25965d075 100644
--- a/src/HelpFile
+++ b/src/HelpFile
@@ -320,13 +320,16 @@ gt, generate_trees: gt Tree?
       the tree.
   options:
       -metas    also return trees that include metavariables
+      -all      generate all (lazily)
+      -lin      linearize result of -all (otherwise, use pipe to linearize)
   flags:
       -depth    generate to this depth (default 3)
       -atoms    take this number of atomic rules of each category (default unlimited)
       -alts     take this number of alternatives at each branch (default unlimited)
       -cat      generate in this category
+      -old      use an older algorithm (usually more memory-consuming)
       -lang     use the abstract syntax of this grammar
-      -number   generate (at most) this number of trees
+      -number   generate (at most) this number of trees (also works with -all)
       -noexpand don't expand these categories (comma-separated, e.g. -noexpand=V,CN)
       -doexpand only expand these categories (comma-separated, e.g. -doexpand=V,CN)
   examples: