diff --git a/Numeric/NumType.lhs b/Numeric/NumType.lhs
--- a/Numeric/NumType.lhs
+++ b/Numeric/NumType.lhs
@@ -68,7 +68,7 @@
 >   , Succ, Negate, Sum, Div, Mul
 >   -- Functions.
 >   , toNum, incr, decr, negate, (+), (-), (*), (/)
->   -- D)ata types.
+>   -- Data types.
 >   , Zero, Pos, Neg
 >   -- Type synonyms for convenience.
 >   , Pos1, Pos2, Pos3, Pos4, Pos5, Neg1, Neg2, Neg3, Neg4, Neg5
@@ -257,7 +257,7 @@
 satisfies its functional dependencies. We provide an instance of
 'Sum' in terms of 'Add' and 'Sub'.
 
-> instance (Add a b c, Sub c b a) => Sum a b c
+> instance (Add a b c, Sub c b a, Sub c a b) => Sum a b c
 
 
 = Division =
diff --git a/changelog.md b/changelog.md
new file mode 100644
--- /dev/null
+++ b/changelog.md
@@ -0,0 +1,21 @@
+1.1 (2014-02)
+-------------
+GHC 7.8.1 compatibility fix.
+
+*  Added a `Sub c b a` constraint to `Sum a b c`. This
+   prevents a liberal coverage condition failure on GHC 7.8.1 RC1.
+
+I don't expect this to break any existing code but am updating
+the major version number just in case.
+
+
+1.0.1 (2013-07)
+---------------
+*  Typeable NumTypes.
+
+
+1.0 (2009-06)
+-------------
+See the [announcement][1].
+
+[1]: http://flygdynamikern.blogspot.se/2009/06/announce-numtype-10-type-level-low.html)
diff --git a/numtype.cabal b/numtype.cabal
--- a/numtype.cabal
+++ b/numtype.cabal
@@ -1,10 +1,10 @@
 Name:                numtype
-Version:             1.0.1
+Version:             1.1
 License:             BSD3
 License-File:        LICENSE
-Copyright:           Bjorn Buckwalter 2009
+Copyright:           Bjorn Buckwalter 2009-2014
 Author:              Bjorn Buckwalter
-Maintainer:          bjorn.buckwalter@gmail.com
+Maintainer:          bjorn@buckwalter.se
 Stability:           stable
 Homepage:            http://dimensional.googlecode.com/
 Synopsis:            Type-level (low cardinality) integers.
@@ -24,4 +24,5 @@
 Build-Depends:       base < 5
 Exposed-Modules:     Numeric.NumType
 Extra-source-files:  README,
+                     changelog.md,
                      Numeric/NumTypeTests.hs