diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## 0.3.0
+### Changed
+- Make conduits polymorphic on input parameter.
+
 ## 0.2.0
 ### Changed
 - Accept read options instead of snapshot for read operations.
diff --git a/rocksdb-query.cabal b/rocksdb-query.cabal
--- a/rocksdb-query.cabal
+++ b/rocksdb-query.cabal
@@ -1,11 +1,13 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.1.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: bcc5b994097bfd7c7418a70ade182d3fc5c268d6b4667e658cb0e5de7727a910
+-- hash: b7e491e8885a215059e085b94eefba33b2304abb0270194e7bae25d74e83b93b
 
 name:           rocksdb-query
-version:        0.2.0
+version:        0.3.0
 synopsis:       RocksDB database querying library for Haskell
 description:    Please see the README on GitHub at <https://github.com/xenog/rocksdb-query#readme>
 category:       Database
@@ -17,16 +19,19 @@
 license:        PublicDomain
 license-file:   UNLICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
 extra-source-files:
-    CHANGELOG.md
     README.md
+    CHANGELOG.md
 
 source-repository head
   type: git
   location: https://github.com/xenog/rocksdb-query
 
 library
+  exposed-modules:
+      Database.RocksDB.Query
+  other-modules:
+      Paths_rocksdb_query
   hs-source-dirs:
       src
   build-depends:
@@ -37,15 +42,13 @@
     , resourcet
     , rocksdb-haskell
     , unliftio
-  exposed-modules:
-      Database.RocksDB.Query
-  other-modules:
-      Paths_rocksdb_query
   default-language: Haskell2010
 
 test-suite rocksdb-query-test
   type: exitcode-stdio-1.0
   main-is: Spec.hs
+  other-modules:
+      Paths_rocksdb_query
   hs-source-dirs:
       test
   ghc-options: -threaded -rtsopts -with-rtsopts=-N
@@ -57,6 +60,4 @@
     , rocksdb-haskell
     , rocksdb-query
     , unliftio
-  other-modules:
-      Paths_rocksdb_query
   default-language: Haskell2010
diff --git a/src/Database/RocksDB/Query.hs b/src/Database/RocksDB/Query.hs
--- a/src/Database/RocksDB/Query.hs
+++ b/src/Database/RocksDB/Query.hs
@@ -48,7 +48,7 @@
        )
     => key
     -> Iterator
-    -> ConduitT () (key, value) m ()
+    -> ConduitT i (key, value) m ()
 matchRecursive base it =
     iterEntry it >>= \case
         Nothing -> return ()
@@ -96,7 +96,7 @@
     => DB
     -> ReadOptions
     -> key
-    -> ConduitT () (key, value) m ()
+    -> ConduitT i (key, value) m ()
 matching db opts base =
     withIterator db opts $ \it -> do
         iterSeek it (encode base)
@@ -114,7 +114,7 @@
     -> ReadOptions
     -> key
     -> key
-    -> ConduitT () (key, value) m ()
+    -> ConduitT i (key, value) m ()
 matchingSkip db opts base start =
     withIterator db opts $ \it -> do
         iterSeek it (encode start)