diff --git a/genCabal.hs b/genCabal.hs
--- a/genCabal.hs
+++ b/genCabal.hs
@@ -8,13 +8,13 @@
 import Control.Applicative
 
 versionInts :: [Word]
-versionInts = [0,34,0,0]
+versionInts = [0,36,0,0]
 
 base :: Package
 base = closedOpen "base" [4,7] [4,9]
 
 rainbow :: Package
-rainbow = nextBreaking "rainbow" [0,24]
+rainbow = nextBreaking "rainbow" [0,26]
 
 text :: Package
 text = closedOpen "text" [0,11,2,0] [1,3]
diff --git a/prednote.cabal b/prednote.cabal
--- a/prednote.cabal
+++ b/prednote.cabal
@@ -3,11 +3,11 @@
 -- http://www.github.com/massysett/cartel
 --
 -- Script name used to generate: genCabal.hs
--- Generated on: 2015-04-25 17:06:29.193914 EDT
+-- Generated on: 2015-04-26 13:32:52.387421 EDT
 -- Cartel library version: 0.14.2.6
 
 name: prednote
-version: 0.34.0.0
+version: 0.36.0.0
 cabal-version: >= 1.18
 license: BSD3
 license-file: LICENSE
@@ -47,7 +47,7 @@
     Prednote.Expressions.RPN
   build-depends:
       base >= 4.7 && < 4.9
-    , rainbow >= 0.24 && < 0.25
+    , rainbow >= 0.26 && < 0.27
     , split >= 0.2.2 && < 0.3
     , text >= 0.11.2.0 && < 1.3
     , containers >= 0.4.2.1 && < 0.6
@@ -86,7 +86,7 @@
     , tasty-th >= 0.1 && < 0.2
     , QuickCheck >= 2.7 && < 2.9
     , base >= 4.7 && < 4.9
-    , rainbow >= 0.24 && < 0.25
+    , rainbow >= 0.26 && < 0.27
     , split >= 0.2.2 && < 0.3
     , text >= 0.11.2.0 && < 1.3
     , containers >= 0.4.2.1 && < 0.6
@@ -124,7 +124,7 @@
     , tasty-th >= 0.1 && < 0.2
     , QuickCheck >= 2.7 && < 2.9
     , base >= 4.7 && < 4.9
-    , rainbow >= 0.24 && < 0.25
+    , rainbow >= 0.26 && < 0.27
     , split >= 0.2.2 && < 0.3
     , text >= 0.11.2.0 && < 1.3
     , containers >= 0.4.2.1 && < 0.6
diff --git a/tests/Rainbow/Instances.hs b/tests/Rainbow/Instances.hs
--- a/tests/Rainbow/Instances.hs
+++ b/tests/Rainbow/Instances.hs
@@ -72,15 +72,21 @@
     . coarbitrary c
 
 
+instance Arbitrary Scheme where
+  arbitrary = Scheme <$> arbitrary <*> arbitrary
+  shrink = genericShrink
+
+instance CoArbitrary Scheme where
+  coarbitrary (Scheme a b) = coarbitrary a . coarbitrary b
+
 instance Arbitrary a => Arbitrary (Chunk a) where
-  arbitrary = Chunk <$> arbitrary <*> arbitrary <*> arbitrary
+  arbitrary = Chunk <$> arbitrary <*> arbitrary
   shrink = genericShrink
 
 instance CoArbitrary a => CoArbitrary (Chunk a) where
-  coarbitrary (Chunk a b c)
+  coarbitrary (Chunk a b)
     = coarbitrary a
     . coarbitrary b
-    . coarbitrary c
 
 instance Arbitrary Radiant where
   arbitrary = Radiant <$> arbitrary <*> arbitrary