diff --git a/CmdDB.hs b/CmdDB.hs
--- a/CmdDB.hs
+++ b/CmdDB.hs
@@ -196,6 +196,14 @@
        , manual = Nothing
        }
   , CommandSpec {
+         command = Doc
+       , commandNames = ["doc", "haddock", "man"]
+       , document = "generate manuals"
+       , routing = RouteCabal ["haddock", "--hyperlink-source"]
+       , switches = []
+       , manual = Nothing
+       }
+  , CommandSpec {
          command = Help
        , commandNames = ["help"]
        , document = "Display the help message of the command"
diff --git a/Types.hs b/Types.hs
--- a/Types.hs
+++ b/Types.hs
@@ -78,6 +78,7 @@
              | Env
              | Add
              | Test
+             | Doc
              | Help
              deriving (Eq,Show)
 
diff --git a/cab.cabal b/cab.cabal
--- a/cab.cabal
+++ b/cab.cabal
@@ -1,5 +1,5 @@
 Name:                   cab
-Version:                0.1.11
+Version:                0.1.12
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3