diff --git a/.travis.yml b/.travis.yml
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,13 +6,18 @@
 
   # Try installing some of the build-deps with apt-get for speed.
   - travis/cabal-apt-install $mode
+  - cabal install packdeps packunused
+  - export PATH=~/.cabal/bin:$PATH
 
 install:
   - cabal configure -flib-Werror $mode
   - cabal build
 
 script:
-  - $script && hlint src --cpp-define HLINT
+  - $script
+  - packdeps approximate.cabal
+  - packunused
+  - hlint src --cpp-define HLINT
 
 notifications:
   irc:
diff --git a/approximate.cabal b/approximate.cabal
--- a/approximate.cabal
+++ b/approximate.cabal
@@ -1,6 +1,6 @@
 name:          approximate
 category:      Numeric
-version:       0.2.1.1
+version:       0.2.2
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
@@ -11,7 +11,7 @@
 bug-reports:   http://github.com/analytics/approximate/issues
 copyright:     Copyright (C) 2013 Edward A. Kmett
 build-type:    Custom
-tested-with:   GHC == 7.4.1, GHC == 7.6.1
+tested-with:   GHC == 7.4.1, GHC == 7.6.1, GHC == 7.8.4, GHC == 7.10.1
 synopsis:      Approximate discrete values and numbers
 description:   This package provides approximate discrete values and numbers.
 
@@ -47,15 +47,13 @@
     cereal                    >= 0.3.5    && < 0.5,
     comonad                   >= 3        && < 5,
     deepseq                   >= 1.3      && < 1.5,
-    distributive              >= 0.3      && < 1,
-    generic-deriving          >= 1.4      && < 1.7,
     ghc-prim,
     hashable                  >= 1.1.2.3  && < 1.3,
     hashable-extras           >= 0.1      && < 1,
     lens                      >= 3.9      && < 5,
     log-domain,
     pointed                   >= 3        && < 5,
-    semigroupoids             >= 3.0.2    && < 5,
+    semigroupoids             >= 3.0.2    && < 6,
     semigroups                >= 0.8.4    && < 1,
     safecopy                  >= 0.8.1    && < 0.9,
     vector                    >= 0.9      && < 0.11
@@ -69,6 +67,8 @@
   if flag(lib-Werror)
     ghc-options: -Werror
 
+  if impl(ghc >= 7.4 && < 7.6)
+    build-depends: ghc-prim
 
   c-sources: cbits/fast.c
   ghc-options: -Wall -fwarn-tabs -O2
@@ -88,9 +88,8 @@
       directory      >= 1.0,
       doctest        >= 0.9.1,
       filepath,
-      generic-deriving,
       semigroups     >= 0.9,
       simple-reflect >= 0.3.1
 
-  if impl(ghc<7.6.1)
+  if impl(ghc<7.6.1) && flag(lib-Werror)
     ghc-options: -Werror
diff --git a/src/Data/Approximate/Mass.hs b/src/Data/Approximate/Mass.hs
--- a/src/Data/Approximate/Mass.hs
+++ b/src/Data/Approximate/Mass.hs
@@ -37,7 +37,7 @@
 import Data.Vector.Generic as G
 import Data.Vector.Generic.Mutable as M
 import Data.Vector.Unboxed as U
-import Generics.Deriving
+import GHC.Generics
 import Numeric.Log
 
 -- | A quantity with a lower-bound on its probability mass. This represents