diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,7 +1,12 @@
 API-ish changes in hledger-lib.
 For user-visible changes, see hledger's change log.
 
-0.27 (unreleased)
+0.27.1 (2016/05/27)
+
+- GHC 8 compatibility
+
+
+0.27 (2015/10/30)
 
 - The main hledger types now derive NFData, which makes it easier to
   time things with criterion.
diff --git a/Hledger/Data/Dates.hs b/Hledger/Data/Dates.hs
--- a/Hledger/Data/Dates.hs
+++ b/Hledger/Data/Dates.hs
@@ -452,6 +452,22 @@
 parsedate :: String -> Day
 parsedate s =  fromMaybe (error' $ "could not parse date \"" ++ s ++ "\"")
                          (parsedateM s)
+-- doctests I haven't been able to make compatible with both GHC 7 and 8
+-- -- >>> parsedate "2008/02/03/"
+-- -- *** Exception: could not parse date "2008/02/03/"
+-- #if MIN_VERSION_base(4,9,0)
+-- -- ...
+-- #endif
+-- #if MIN_VERSION_time(1,6,0)
+-- -- >>> parsedate "2008/02/30"  -- with time >= 1.6, invalid dates are rejected
+-- -- *** Exception: could not parse date "2008/02/30"
+-- #if MIN_VERSION_base(4,9,0)
+-- -- ...
+-- #endif
+-- #else
+-- -- >>> parsedate "2008/02/30"  -- with time < 1.6, they are silently adjusted
+-- -- 2008-02-29
+-- #endif
 
 -- | Parse a time string to a time type using the provided pattern, or
 -- return the default.
@@ -738,7 +754,7 @@
 nulldatespan = DateSpan Nothing Nothing
 
 nulldate :: Day
-nulldate = parsedate "0000/00/00"
+nulldate = parsedate "0000/01/01"
 
 tests_Hledger_Data_Dates = TestList
  [
diff --git a/hledger-lib.cabal b/hledger-lib.cabal
--- a/hledger-lib.cabal
+++ b/hledger-lib.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           hledger-lib
-version:        0.27
+version:        0.27.1
 stability:      stable
 category:       Finance
 synopsis:       Core data types, parsers and functionality for the hledger accounting tools
@@ -23,7 +23,7 @@
 bug-reports:    http://bugs.hledger.org
 cabal-version:  >= 1.10
 build-type:     Simple
-tested-with:    GHC==7.4.2, GHC==7.6.3, GHC==7.8.4, GHC==7.10.2
+tested-with:    GHC==7.6.3, GHC==7.8.4, GHC==7.10.3, GHC==8.0.1
 
 extra-source-files:
     CHANGES 
@@ -69,7 +69,7 @@
     , regex-tdfa
     , safe >= 0.2
     , split >= 0.1 && < 0.3
-    , transformers >= 0.2 && < 0.5
+    , transformers >= 0.2 && < 0.6
     , uglymemo
     , utf8-string >= 0.3.5 && < 1.1
     , HUnit
@@ -147,7 +147,7 @@
     , regex-tdfa
     , safe >= 0.2
     , split >= 0.1 && < 0.3
-    , transformers >= 0.2 && < 0.5
+    , transformers >= 0.2 && < 0.6
     , uglymemo
     , utf8-string >= 0.3.5 && < 1.1
     , HUnit