diff --git a/Check.hs b/Check.hs
index 3ae4929..e27736b 100644
--- a/Check.hs
+++ b/Check.hs
@@ -23,12 +23,7 @@ check opt cradle fileName = withGHC fileName $ checkIt `gcatch` handleErrMsg
     checkIt = do
         readLog <- initializeFlagsWithCradle opt cradle options True
         setTargetFile fileName
-        -- To check TH, a session module graph is necessary.
-        -- "load" sets a session module graph using "depanal".
-        -- But we have to set "-fno-code" to DynFlags before "load".
-        -- So, this is necessary redundancy.
-        slow <- needsTemplateHaskell <$> depanal [] False
-        when slow setSlowDynFlags
+        checkSlowAndSet
         void $ load LoadAllTargets
         liftIO readLog
     options
diff --git a/GHCApi.hs b/GHCApi.hs
index c34448f..d3eee88 100644
--- a/GHCApi.hs
+++ b/GHCApi.hs
@@ -5,7 +5,7 @@ module GHCApi (
   , initializeFlagsWithCradle
   , setTargetFile
   , getDynamicFlags
-  , setSlowDynFlags
+  , checkSlowAndSet
   ) where
 
 import CabalApi
@@ -122,6 +122,15 @@ setSlowDynFlags :: Ghc ()
 setSlowDynFlags = (flip setFastOrNot False <$> getSessionDynFlags)
                   >>= void . setSessionDynFlags
 
+-- To check TH, a session module graph is necessary.
+-- "load" sets a session module graph using "depanal".
+-- But we have to set "-fno-code" to DynFlags before "load".
+-- So, this is necessary redundancy.
+checkSlowAndSet :: Ghc ()
+checkSlowAndSet = do
+    slow <- needsTemplateHaskell <$> depanal [] False
+    when slow setSlowDynFlags
+
 ----------------------------------------------------------------
 
 modifyFlagsWithOpts :: DynFlags -> [String] -> Ghc DynFlags
diff --git a/Info.hs b/Info.hs
index c9cc467..12f290d 100644
--- a/Info.hs
+++ b/Info.hs
@@ -4,7 +4,7 @@
 module Info (infoExpr, typeExpr) where
 
 import Control.Applicative
-import Control.Monad (when)
+import Control.Monad (void)
 import CoreUtils
 import Data.Function
 import Data.Generics
@@ -144,18 +144,16 @@ inModuleContext opt cradle fileName modstr action errmsg =
     withGHCDummyFile (valid ||> invalid ||> return errmsg)
   where
     valid = do
-        _ <- initializeFlagsWithCradle opt cradle ["-w"] False
+        void $ initializeFlagsWithCradle opt cradle ["-w"] False
         setTargetFile fileName
-        slow <- needsTemplateHaskell <$> depanal [] False
-        when slow setSlowDynFlags
-        _ <- load LoadAllTargets
+        checkSlowAndSet
+        void $ load LoadAllTargets
         doif setContextFromTarget action
     invalid = do
-        _ <- initializeFlagsWithCradle opt cradle ["-w"] False
+        void $ initializeFlagsWithCradle opt cradle ["-w"] False
         setTargetBuffer
-        slow <- needsTemplateHaskell <$> depanal [] False
-        when slow setSlowDynFlags
-        _ <- load LoadAllTargets
+        checkSlowAndSet
+        void $ load LoadAllTargets
         doif setContextFromTarget action
     setTargetBuffer = do
         modgraph <- depanal [mkModuleName modstr] True