diff --git a/library/VectorBuilder/MonadPlus.hs b/library/VectorBuilder/MonadPlus.hs
--- a/library/VectorBuilder/MonadPlus.hs
+++ b/library/VectorBuilder/MonadPlus.hs
@@ -14,7 +14,7 @@
 {-# INLINABLE many #-}
 many :: MonadPlus m => m a -> m (Vector a)
 many m =
-  fmap B.build loop
+  liftM B.build loop
   where
     loop =
       mplus
@@ -32,7 +32,7 @@
 {-# INLINABLE sepBy1 #-}
 sepBy1 :: MonadPlus m => m element -> m separator -> m (Vector element)
 sepBy1 elementM separatorM =
-  fmap B.build loop
+  liftM B.build loop
   where
     loop =
       do
diff --git a/vector-builder.cabal b/vector-builder.cabal
--- a/vector-builder.cabal
+++ b/vector-builder.cabal
@@ -1,7 +1,7 @@
 name:
   vector-builder
 version:
-  0.3.4
+  0.3.4.1
 synopsis:
   Vector builder
 description: