1 files changed, 1 insertions, 0 deletions

diff --git a/src/Crypto/Macaroon/Verifier.hs b/src/Crypto/Macaroon/Verifier.hs
index 02cb448..ed24ea4 100644
--- a/src/Crypto/Macaroon/Verifier.hs
+++ b/src/Crypto/Macaroon/Verifier.hs
@@ -32,6 +32,7 @@ import           Data.Byteable
 import           Data.Foldable
 import           Data.Function
 import           Data.Maybe
+import           Data.Monoid
 import           Data.Traversable
 import Data.Attoparsec.ByteString
 import Data.Attoparsec.ByteString.Char8