diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -12,7 +12,9 @@
 ## Using inventory
 
 Install with `stack update && stack install inventory` or `cabal update &&
-cabal install inventory`.
+cabal install inventory`. The version used to compile `inventory` must be the
+same as the version used to compile your project. For stack users, this means
+you may have to `stack install` from within your project to use the right GHC.
 
 Inventory uses `.hie` files to gather information about all haskell files in
 the project. Once you have generated `.hie` files for your project, execute
@@ -80,5 +82,3 @@
 - Standalone kind signatures are not yet included in definition counts.
 - Does not unfold type synonyms when comparing type signatures.
 - GHC versions other than 8.8, 8.10, and 9.0 are not currently supported.
-- You may encounter errors if the version of GHC used to compile `inventory` is
-  different from the version used to compile your project.
diff --git a/inventory.cabal b/inventory.cabal
--- a/inventory.cabal
+++ b/inventory.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: fee986bf906b9590bf18ee9a5c29116d193fe782a4027076edfdc92f4e418ce3
+-- hash: 2c217de02982da803d30a671d986dea8bc36b776a638aafdd2b1599609a962f1
 
 name:           inventory
-version:        0.1.0.1
+version:        0.1.0.2
 synopsis:       Project statistics and definition analysis
 description:    Please see the README on GitHub at <https://github.com/aaronallen8455/inventory#readme>
 category:       Utility
diff --git a/src/HieFile.hs b/src/HieFile.hs
--- a/src/HieFile.hs
+++ b/src/HieFile.hs
@@ -20,6 +20,7 @@
 import           Data.Monoid
 import           System.Directory (canonicalizePath, doesDirectoryExist, doesFileExist, doesPathExist, listDirectory, withCurrentDirectory)
 import           System.Environment (lookupEnv)
+import           System.Exit (exitFailure)
 import           System.FilePath (isExtensionOf)
 
 import           DefCounts.ProcessHie
@@ -57,8 +58,12 @@
 getHieFiles = do
   hieDir <- fromMaybe ".hie" <$> lookupEnv "HIE_DIR"
   filePaths <- getHieFilesIn hieDir
-    `onException` error "HIE file directory does not exist"
-  when (null filePaths) . error $ "No HIE files found in dir: " <> hieDir
+    `onException` do
+      putStrLn ("HIE file directory does not exist: " <> show hieDir)
+      exitFailure
+  when (null filePaths) $ do
+    putStrLn $ "No HIE files found in dir: " <> show hieDir
+    exitFailure
   hieFiles <- hieFilesFromPaths filePaths
   let srcFileExists = doesPathExist . hie_hs_file
   filterM srcFileExists hieFiles
@@ -69,9 +74,16 @@
 hieFilesFromPaths filePaths = do
   nameCacheRef <- newIORef =<< mkNameCache
   let updater = NCU $ atomicModifyIORef' nameCacheRef
-  traverse (fmap hie_file_result . readHieFile updater)
-           filePaths
+  traverse (getHieFile updater) filePaths
 
+getHieFile :: NameCacheUpdater -> FilePath -> IO HieFile
+getHieFile ncUpdater filePath =
+  handleHieVersionMismatch filePath . fmap hie_file_result
+    =<< readHieFileWithVersion
+          (\(v, _) -> v == hieVersion)
+          ncUpdater
+          filePath
+
 #else
 
 hieFilesFromPaths :: [FilePath] -> IO [HieFile]
@@ -81,9 +93,24 @@
 
 getHieFile :: FilePath -> StateT NameCache IO HieFile
 getHieFile filePath = StateT $ \nameCache ->
-  first hie_file_result <$> readHieFile nameCache filePath
+  handleHieVersionMismatch filePath . fmap (first hie_file_result)
+    =<< readHieFileWithVersion
+          (\(v, _) -> v == hieVersion)
+          nameCache
+          filePath
 
 #endif
+
+handleHieVersionMismatch :: FilePath -> Either HieHeader a -> IO a
+handleHieVersionMismatch path = either errMsg pure where
+  errMsg (ver, _ghcVer) = do
+    putStrLn $ unlines
+      [ "Incompatible hie file: " <> path
+      , "hie files must be generated with the same GHC version used to compile inventory"
+      , "Inventory was compiled with GHC version " <> show hieVersion
+      , "The hie files for this project were generated with version " <> show ver
+      ]
+    exitFailure
 
 mkNameCache :: IO NameCache
 mkNameCache = do