diff --git a/lib/coin-selection/test/spec/Cardano/CoinSelection/BalanceSpec.hs b/lib/coin-selection/test/spec/Cardano/CoinSelection/BalanceSpec.hs
index b63e05917e2..1358d278800 100644
--- a/lib/coin-selection/test/spec/Cardano/CoinSelection/BalanceSpec.hs
+++ b/lib/coin-selection/test/spec/Cardano/CoinSelection/BalanceSpec.hs
@@ -1070,7 +1070,7 @@ prop_performSelection mockConstraints params coverage =
         --
         -- We expect that the selection should succeed.
         --
-        let constraints' :: SelectionConstraints TestSelectionContext =
+        let constraints' =
                 constraints
                     { assessTokenBundleSize = unMockAssessTokenBundleSize
                         MockAssessTokenBundleSizeUnlimited
@@ -1078,7 +1078,7 @@ prop_performSelection mockConstraints params coverage =
                         const computeMinimumAdaQuantityZero
                     , computeMinimumCost = computeMinimumCostZero
                     , computeSelectionLimit = const NoLimit
-                    }
+                    }  :: SelectionConstraints TestSelectionContext
             performSelection' = performSelection constraints' params
         in
         monadicIO $ run performSelection' >>= \case
diff --git a/lib/coin-selection/test/spec/Cardano/CoinSelectionSpec.hs b/lib/coin-selection/test/spec/Cardano/CoinSelectionSpec.hs
index 2a8599fd04a..863ac97fae2 100644
--- a/lib/coin-selection/test/spec/Cardano/CoinSelectionSpec.hs
+++ b/lib/coin-selection/test/spec/Cardano/CoinSelectionSpec.hs
@@ -457,7 +457,11 @@ prop_prepareOutputsWith_twice minCoinValueDef outs =
     once === twice
   where
     minCoinValueFor = unMockComputeMinimumAdaQuantity minCoinValueDef
-    (_:once:twice:_) = iterate (prepareOutputsWith minCoinValueFor) outs
+    (once, twice) =
+      case iterate (prepareOutputsWith minCoinValueFor) outs of
+        (_:a:b:_) -> (a, b)
+        _else -> error "prop_prepareOutputsWith_twice"
+
 
 prop_prepareOutputsWith_length
     :: MockComputeMinimumAdaQuantity
diff --git a/lib/primitive/test/spec/Cardano/Wallet/Primitive/Types/TokenMapSpec.hs b/lib/primitive/test/spec/Cardano/Wallet/Primitive/Types/TokenMapSpec.hs
index b1c175a26ed..890b07f7cbd 100644
--- a/lib/primitive/test/spec/Cardano/Wallet/Primitive/Types/TokenMapSpec.hs
+++ b/lib/primitive/test/spec/Cardano/Wallet/Primitive/Types/TokenMapSpec.hs
@@ -384,7 +384,10 @@ prop_subtract_invariant :: TokenMap -> TokenMap -> Property
 prop_subtract_invariant m1 m2 = property $
     m2 `leq` m1 ==> invariantHolds result
   where
-    Just result = TokenMap.subtract m1 m2
+    result =
+      case TokenMap.subtract m1 m2 of
+        Nothing -> error "prop_subtract_invariant"
+        Just r -> r
 
 prop_difference_invariant :: TokenMap -> TokenMap -> Property
 prop_difference_invariant m1 m2 =
diff --git a/lib/wallet/src/Cardano/Wallet/Pools.hs b/lib/wallet/src/Cardano/Wallet/Pools.hs
index b7a667a131e..1a2749e6fd0 100644
--- a/lib/wallet/src/Cardano/Wallet/Pools.hs
+++ b/lib/wallet/src/Cardano/Wallet/Pools.hs
@@ -436,8 +436,8 @@ combineDbAndLsqData ti nOpt lsqData =
         = Coin
         $ average
         $ L.take nOpt
-        $ L.sort
-        $ map (Down . unCoin . view #nonMyopicMemberRewards)
+        $ L.sortOn Down
+        $ map (unCoin . view #nonMyopicMemberRewards)
         $ Map.elems lsqData
       where
         average [] = 0
diff --git a/lib/wallet/src/Cardano/Wallet/Read/Tx/Witnesses.hs b/lib/wallet/src/Cardano/Wallet/Read/Tx/Witnesses.hs
index 50f6659fcde..5f8a4c7fc4b 100644
--- a/lib/wallet/src/Cardano/Wallet/Read/Tx/Witnesses.hs
+++ b/lib/wallet/src/Cardano/Wallet/Read/Tx/Witnesses.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE DataKinds #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE UndecidableInstances #-}