diff --git a/Test/Chuchu.hs b/Test/Chuchu.hs
--- a/Test/Chuchu.hs
+++ b/Test/Chuchu.hs
@@ -59,10 +59,10 @@
 --defs
 --  = do
 --    Given
---      ("that I have entered " *> number <* " into the calculator")
+--      (\"that I have entered \" *> number <* \" into the calculator\")
 --      enterNumber
---    When "I press divide" $ const divide
---    Then ("the result should be " *> number <* " on the screen")
+--    When \"I press divide\" $ const divide
+--    Then (\"the result should be \" *> number <* \" on the screen\")
 --      $ \\n
 --        -> do
 --          d <- getDisplay
diff --git a/Test/Chuchu/Parser.hs b/Test/Chuchu/Parser.hs
--- a/Test/Chuchu/Parser.hs
+++ b/Test/Chuchu/Parser.hs
@@ -25,7 +25,10 @@
 import Test.Chuchu.Email
 
 instance IsString (Parser a) where
-  fromString s = void (string s) >> return undefined
+  fromString s
+    = void (string s)
+      >> return
+        (error $ "The return value of string parsers should not be used")
 
 -- | Parses a floating point number, with the same syntax as accepted by
 -- Haskell.
diff --git a/Test/Chuchu/Types.hs b/Test/Chuchu/Types.hs
--- a/Test/Chuchu/Types.hs
+++ b/Test/Chuchu/Types.hs
@@ -36,7 +36,7 @@
 
 instance Monad (ChuchuM m) where
   return _ = Nil
-  step >>= k = Cons step $ k undefined
+  step >>= k = Cons step $ k $ error "(>>=): ChuchuM does not support 'return'."
 
 -- | Converts the Monad into a single 'Parser' that executes the specified
 -- action if the parser is executed correctly.  It includes an 'eof' on the
diff --git a/chuchu.cabal b/chuchu.cabal
--- a/chuchu.cabal
+++ b/chuchu.cabal
@@ -1,5 +1,5 @@
 name: chuchu
-version: 0.0.0.0
+version: 0.0.0.1
 cabal-version: >= 1.8
 build-type: Simple
 license: OtherLicense
@@ -10,7 +10,7 @@
 stability: experimental
 homepage: http://github.com/marcotmarcot/chuchu
 bug-reports: http://github.com/marcotmarcot/chuchu/issues
-synopsis: Behaviour Driven Development for Haskell
+synopsis: Behaviour Driven Development like Cucumber for Haskell
 description:
   Chuchu is a system similar to Ruby's Cucumber for Behaviour Driven
   Development.  It works with a language similar to Cucumber's Gherkin, which is