diff --git a/server/PandocServer.hs b/server/PandocServer.hs
index bf510e670..295412c6d 100644
--- a/server/PandocServer.hs
+++ b/server/PandocServer.hs
@@ -27,6 +27,7 @@ import qualified Data.ByteString as BS
 import qualified Data.ByteString.Lazy as BL
 import Data.ByteString.Base64 (decodeBase64, encodeBase64)
 import Data.Default
+import Data.Map (Map)
 import Data.Set (Set)
 import Skylighting (defaultSyntaxMap)