diff --git a/src/RWS.hs b/src/RWS.hs
index a5d767884..5daf4ff3a 100644
--- a/src/RWS.hs
+++ b/src/RWS.hs
@@ -4,7 +4,7 @@ module RWS
 , Options(..)
 , defaultOptions
 , ComparabilityRelation
-, FeatureVector(..)
+, FeatureVector
 , defaultFeatureVectorDecorator
 , featureVectorDecorator
 , pqGramDecorator