diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,9 @@
 # trace-embrace changelog
 
+## Version 1.0.8 2025-03-14
+  * bugfix: serialize test compilation with [th-lock](https://hackage.haskell.org/package/th-lock)
+  * bugfix: serialize yaml config loading and on demand initialization
+
 ## Version 1.0.4 2025-03-11
   * bugfix: multiple traces on the same line
 
diff --git a/src/Debug/TraceEmbrace/Config/Load.hs b/src/Debug/TraceEmbrace/Config/Load.hs
--- a/src/Debug/TraceEmbrace/Config/Load.hs
+++ b/src/Debug/TraceEmbrace/Config/Load.hs
@@ -82,10 +82,15 @@
 loadYamlConfig :: IO YamlConfig
 loadYamlConfig = do
   doesFileExist fp >>= \case
-    True -> configFromJust . (<> defaultYamlConfig) =<< catch (Y.decodeFileThrow fp) badYaml
+    True -> do
+      putStrLn $ "Loading existish trace-embrace config from [" <> fp <> "]"
+      configFromJust . (<> defaultYamlConfig) =<< catch (Y.decodeFileThrow fp) badYaml
     False -> do
-      Y.encodeFile fp newYamlConfig
-      traceIO $ "New default config trace-embrace file is generated: [" <> fp <> "]"
+      catch (do
+                Y.encodeFile fp newYamlConfig
+                putStrLn $ "New default config trace-embrace file is generated: [" <> fp <> "]")
+            (\e -> putStrLn $ "Failed to create config file [" <> fp <> "] due: " <>
+              prettyPrintParseException e)
       configFromJust newYamlConfig
   where
     configFromJust :: YamlConfigMaybe -> IO YamlConfig
@@ -125,17 +130,30 @@
   (mkPrefixTree . unrefine $ yc.levels)
   (unrefine $ yc.runtimeLevelsOverrideEnvVar)
 
+configReadToken :: MVar ()
+configReadToken = unsafePerformIO (newMVar ())
+{-# NOINLINE configReadToken #-}
+
 getConfig :: Q TraceEmbraceConfig
 getConfig = do
-  c <- runIO (readIORef traceEmbraceConfigRef) >>= loadIfNothing
+  c <- runIO readConfigRef >>= loadIfNothing
   addDependentFile traceEmbraceConfigFileName
   pure c
   where
+    readConfigRef = readIORef traceEmbraceConfigRef
     loadIfNothing = \case
-      Nothing -> do
-        c <- yaml2Config <$> runIO loadYamlConfig
-        runIO (atomicWriteIORef traceEmbraceConfigRef (Just c))
-        pure c
+      Nothing -> runIO $ do
+        bracket (takeMVar configReadToken)
+          (putMVar configReadToken)
+          (\() ->
+             readConfigRef >>= \case
+               Just c -> do
+                 putStrLn "trace-embrace.yaml Config is already loaded after resume"
+                 pure c
+               Nothing -> do
+                 c <- yaml2Config <$> loadYamlConfig
+                 (atomicWriteIORef traceEmbraceConfigRef (Just c))
+                 pure c)
       Just c -> pure c
 
 traceAll :: [LeveledModulePrefix]
diff --git a/src/Debug/TraceEmbrace/Config/Type/Mode.hs b/src/Debug/TraceEmbrace/Config/Type/Mode.hs
--- a/src/Debug/TraceEmbrace/Config/Type/Mode.hs
+++ b/src/Debug/TraceEmbrace/Config/Type/Mode.hs
@@ -23,7 +23,7 @@
   | TraceStd
   | TraceUnsafeIo { sink :: IoSink }
   | TraceEvent
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Lift)
 
 instance ToJSON SinkMode where
   toEncoding = genericToEncoding defaultOptions
diff --git a/src/Debug/TraceEmbrace/Internal/TH.hs b/src/Debug/TraceEmbrace/Internal/TH.hs
--- a/src/Debug/TraceEmbrace/Internal/TH.hs
+++ b/src/Debug/TraceEmbrace/Internal/TH.hs
@@ -337,18 +337,21 @@
                         (wrap x))
        |]
 
+chooseTraceIoFunOnTh :: Show s => TraceEmbraceConfig -> s -> Q Exp
+chooseTraceIoFunOnTh c s =
+  case c ^. #mode of
+    TraceDisabled -> fail $ "Dead code on" <> show s
+    TraceStd -> pure $ VarE 'T.traceIO
+    TraceUnsafeIo snk -> [| hPutStrLn (getSinkHandle snk) |]
+    TraceEvent -> pure $ VarE 'T.traceEventIO
+
 trIo :: Q Exp -> String -> Q Exp
 trIo idF rawMsg = do
   c <- getConfig
   traceG c idF (go c) rawMsg
   where
-    go c s fmt = do
-      let trFun = case c ^. #mode of
-                    TraceDisabled -> error $ "Dead code on" <> show s
-                    TraceStd -> 'T.traceIO
-                    TraceUnsafeIo _ -> 'safePutStrLn
-                    TraceEvent -> 'T.traceEventIO
-      [| $(varE trFun) $(traceMessage s fmt svars) |]
+    go c s fmt =
+      [| $(chooseTraceIoFunOnTh c s) $(traceMessage s fmt svars) |]
 
 trFunMarker :: Q Exp -> Q Exp
 trFunMarker idF = do
diff --git a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH.hs b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH.hs
--- a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH.hs
+++ b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH.hs
@@ -1,12 +1,17 @@
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE OverloadedRecordDot #-}
 -- {-# OPTIONS_GHC -ddump-splices #-}
 module Debug.TraceEmbrace.Test.TraceEmbrace.TH where
 
 import Data.ByteString.Lazy
 import Debug.TraceEmbrace
 import Debug.TraceEmbrace.Test.TraceEmbrace.Config
+import Language.Haskell.TH.Lock
+import Language.Haskell.TH.Syntax
 import Test.Tasty.HUnit ((@=?))
 
+ensureSerialCompilationVerbose
+
 unit_tr_trace :: IO ()
 unit_tr_trace = withPrefixEnvVar thresholdConfig "" $ go one
   where
@@ -55,9 +60,13 @@
     go x = x @=? foo x
     foo x = $(tw' "tw foo/x") x
 
--- unit_trIo :: IO ()
--- unit_trIo = withPrefixEnvVar thresholdConfig "" $ go one
---   where
---     go x = (x @=?) =<< foo x
---       where
---         foo y = $(trIo "foo info/y") >> pure y
+unit_trIo :: IO ()
+unit_trIo = withPrefixEnvVar thresholdConfig "" $ go one
+  where
+    go x = (x @=?) =<< foo x
+      where
+        foo y = $(trIo "foo info/y") >> pure y
+
+unit_ensure_mode_trace_std :: IO ()
+unit_ensure_mode_trace_std =
+  $( lift =<< ((.mode) <$> getConfig)  ) @=? TraceStd
diff --git a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Event.hs b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Event.hs
--- a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Event.hs
+++ b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Event.hs
@@ -5,8 +5,11 @@
 import Debug.TraceEmbrace.Config.Type
 import Debug.TraceEmbrace.Internal.TH
 import Debug.TraceEmbrace.Test.TraceEmbrace.Config
+import Language.Haskell.TH.Lock
 import Test.Tasty.HUnit ((@=?))
 import System.Directory
+
+ensureSerialCompilationVerbose
 
 unit_unsafeio_stderr_mode :: IO ()
 unit_unsafeio_stderr_mode =
diff --git a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Lifted.hs b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Lifted.hs
--- a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Lifted.hs
+++ b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Lifted.hs
@@ -5,10 +5,14 @@
 import Data.ByteString.Lazy
 import Debug.TraceEmbrace.Internal.TH
 import Debug.TraceEmbrace.Test.TraceEmbrace.Config
+import Language.Haskell.TH.Lock
 import Test.Tasty.HUnit ((@=?))
 
 -- not working: https://gitlab.haskell.org/ghc/ghc/-/issues/25775
 default (Int)
+
+
+ensureSerialCompilationVerbose
 
 unit_traceMessage_const :: IO ()
 unit_traceMessage_const =
diff --git a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Unboxed.hs b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Unboxed.hs
--- a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Unboxed.hs
+++ b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Format/Unboxed.hs
@@ -9,7 +9,11 @@
 import Debug.TraceEmbrace
 import Debug.TraceEmbrace.Test.TraceEmbrace.Config
 import GHC.Exts
+import Language.Haskell.TH.Lock
 import Test.Tasty.HUnit ((@=?))
+
+
+ensureSerialCompilationVerbose
 
 unit_unboxed_int :: IO ()
 unit_unboxed_int = "foo; x#: 1#" @=? foo one
diff --git a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Threshold.hs b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Threshold.hs
--- a/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Threshold.hs
+++ b/test/Debug/TraceEmbrace/Test/TraceEmbrace/TH/Threshold.hs
@@ -7,10 +7,12 @@
 import Debug.TraceEmbrace.Internal.TH qualified as I
 import Debug.TraceEmbrace.Config
 import Debug.TraceEmbrace.Test.TraceEmbrace.Config
+import Language.Haskell.TH.Lock
 import System.FilePath
 import System.IO.Temp
 import Test.Tasty.HUnit ((@=?))
 
+ensureSerialCompilationVerbose
 
 unit_mode_disabled :: IO ()
 unit_mode_disabled =
diff --git a/trace-embrace.cabal b/trace-embrace.cabal
--- a/trace-embrace.cabal
+++ b/trace-embrace.cabal
@@ -1,6 +1,6 @@
 cabal-version:   3.0
 name:            trace-embrace
-version:         1.0.5
+version:         1.0.10
 license:         BSD-3-Clause
 license-file:    LICENSE
 category:        Development
@@ -442,6 +442,7 @@
     , template-haskell
     , temporary < 1.5
     , text
+    , th-lock < 1.0.0
     , trace-embrace
     , yaml
   default-language: Haskell2010