diff --git a/hw-balancedparens.cabal b/hw-balancedparens.cabal
--- a/hw-balancedparens.cabal
+++ b/hw-balancedparens.cabal
@@ -1,7 +1,7 @@
 cabal-version:  2.2
 
 name:           hw-balancedparens
-version:        0.2.2.0
+version:        0.2.2.1
 synopsis:       Balanced parentheses
 description:    Balanced parentheses.
 category:       Data, Bit, Succinct Data Structures, Data Structures
diff --git a/src/HaskellWorks/Data/BalancedParens/RangeMinMax.hs b/src/HaskellWorks/Data/BalancedParens/RangeMinMax.hs
--- a/src/HaskellWorks/Data/BalancedParens/RangeMinMax.hs
+++ b/src/HaskellWorks/Data/BalancedParens/RangeMinMax.hs
@@ -46,7 +46,7 @@
   , rangeMinMaxL1Excess :: !(DVS.Vector Int16)
   , rangeMinMaxL2Min    :: !(DVS.Vector Int16)
   , rangeMinMaxL2Excess :: !(DVS.Vector Int16)
-  } deriving (NFData, Generic)
+  } deriving (Eq, NFData, Generic)
 
 factorL0 :: Integral a => a
 factorL0 = 1