diff --git a/hledger-lib/Hledger/Utils/Test.hs b/hledger-lib/Hledger/Utils/Test.hs
index 0b967ff4e..08a69d0d9 100644
--- a/hledger-lib/Hledger/Utils/Test.hs
+++ b/hledger-lib/Hledger/Utils/Test.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}