diff --git a/.fixme-new/fixme.log b/.fixme-new/fixme.log
index ebb11202..5017bfe8 100644
Binary files a/.fixme-new/fixme.log and b/.fixme-new/fixme.log differ
diff --git a/hbs2-tests/hbs2-tests.cabal b/hbs2-tests/hbs2-tests.cabal
index df2b18b2..8e607b09 100644
--- a/hbs2-tests/hbs2-tests.cabal
+++ b/hbs2-tests/hbs2-tests.cabal
@@ -1040,3 +1040,45 @@ executable test-merge-limits
         , unordered-containers
         , unix
         , timeit
+
+
+executable test-lsw-write
+    import:           shared-properties
+    default-language: Haskell2010
+
+    -- other-extensions:
+
+    hs-source-dirs:   test
+    main-is:          TestLSMWrite.hs
+    build-depends:
+          base, hbs2-core, hbs2-storage-simple
+        , async
+        , bytestring
+        , cache
+        , containers
+        , hashable
+        , microlens-platform
+        , mtl
+        , prettyprinter
+        , QuickCheck
+        , quickcheck-instances
+        , random
+        , safe
+        , serialise
+        , stm
+        , streaming
+        , tasty
+        , tasty-quickcheck
+        , tasty-hunit
+        , tasty-quickcheck
+        , transformers
+        , uniplate
+        , vector
+        , filepath
+        , temporary
+        , unliftio
+        , unordered-containers
+        , unix
+        , timeit
+
+
diff --git a/hbs2-tests/test/TestLSMWrite.hs b/hbs2-tests/test/TestLSMWrite.hs
new file mode 100644
index 00000000..724aa0f6
--- /dev/null
+++ b/hbs2-tests/test/TestLSMWrite.hs
@@ -0,0 +1,36 @@
+{-# Language NumericUnderscores #-}
+module Main where
+
+import HBS2.Prelude.Plated
+
+import HBS2.Hash
+import HBS2.Data.Types.Refs
+import HBS2.Storage.Compact
+
+import Data.ByteString.Builder qualified as B
+import Data.ByteString.Lazy qualified as LBS
+import Data.ByteString.Char8 qualified as BS8
+import Data.Function
+import Streaming.Prelude qualified as S
+import System.TimeIt
+import Data.HashSet qualified as HS
+import Data.HashSet (HashSet)
+import Data.List qualified as List
+import UnliftIO
+import System.Random
+import Data.Word
+import Control.Monad
+import System.Environment
+
+main :: IO ()
+main = do
+  [f] <- getArgs
+  sto <- compactStorageOpen @HbSync mempty f
+
+  for_ [0..10_000_000] $ \i -> do
+    let k = B.toLazyByteString (B.word64BE i) & LBS.toStrict
+    let v = BS8.pack (show k)
+    put sto k v
+
+  compactStorageClose sto
+