diff --git a/tests/Database/HDBC/Mock.hs b/tests/Database/HDBC/Mock.hs
--- a/tests/Database/HDBC/Mock.hs
+++ b/tests/Database/HDBC/Mock.hs
@@ -50,6 +50,7 @@
     , tryReadTChan
     , newTChanIO
     )
+import Data.Semigroup
 
 data MockConnection =
     MockConnection
@@ -161,6 +162,8 @@
     mempty = anything
     mappend (Constraint a) (Constraint b) =
         Constraint (\x -> a x && b x)
+
+instance Semigroup (Constraint a) where
 
 (<||>) :: Constraint a -> Constraint a -> Constraint a
 a <||> b = Constraint $ \x -> check a x || check b x
diff --git a/yeshql-hdbc.cabal b/yeshql-hdbc.cabal
--- a/yeshql-hdbc.cabal
+++ b/yeshql-hdbc.cabal
@@ -1,5 +1,5 @@
 name: yeshql-hdbc
-version: 4.1.0.0
+version: 4.1.0.1
 synopsis: YesQL-style SQL database abstraction (HDBC backend)
 description: Use quasi-quotations or TemplateHaskell to write SQL in SQL, while
              adding type annotations to turn SQL into well-typed Haskell