diff --git a/flexible-defaults.cabal b/flexible-defaults.cabal
--- a/flexible-defaults.cabal
+++ b/flexible-defaults.cabal
@@ -1,5 +1,5 @@
 name:                   flexible-defaults
-version:                0.0.2
+version:                0.0.3
 stability:              provisional
 
 cabal-version:          >= 1.6
@@ -32,7 +32,7 @@
 
 tested-with:            GHC == 7.0.4, GHC == 7.2.2, GHC == 7.4.2, GHC == 7.6.3,
                         GHC == 7.8.4, GHC == 7.10.3, GHC == 8.0.2, GHC == 8.2.2,
-                        GHC == 8.4.3
+                        GHC == 8.4.4, GHC == 8.6.5, GHC == 8.8.1
 
 source-repository head
   type:                 git
diff --git a/src/Language/Haskell/TH/FlexibleDefaults/DSL.hs b/src/Language/Haskell/TH/FlexibleDefaults/DSL.hs
--- a/src/Language/Haskell/TH/FlexibleDefaults/DSL.hs
+++ b/src/Language/Haskell/TH/FlexibleDefaults/DSL.hs
@@ -111,7 +111,7 @@
     (oldS, deps, inl) <- get
     case oldS of
         Nothing -> put (Just s, deps, inl)
-        Just _  -> fail "score: score was already set"
+        Just _  -> error "score: score was already set"
 
 -- |Specify the cost (negated score) associated with the current implementation.
 -- Only one invocation of either 'score' or 'cost' may be used per implementation.