diff --git a/Main.hs b/Main.hs
index 64df6ff..62eee1f 100644
--- a/Main.hs
+++ b/Main.hs
@@ -192,8 +192,11 @@ deleteLocalStorage = do
   whitelist <- asks whitelist
   let path = webengine </> "Local Storage" </> "leveldb"
 
+  dbIsOk <- liftIO $ D.doesFileExist (path </> "LOCK")
+  when (not dbIsOk) (throwError "Database is missing or corrupted")
+
   version <- withDB path (\db -> L.get db def "VERSION")
-  when (version /= Just "1") (throwError "Unsupported schema version")
+  when (version /= Just "1") (throwError "Database is empty or the schema unsupported")
 
   withDB path $ \db -> do
     badDomains <- L.withIterator db def $ \i ->
@@ -234,8 +237,11 @@ deleteSessionStorage = do
   whitelist <- asks whitelist
   let path = webengine </> "Session Storage"
 
+  dbIsOk <- liftIO $ D.doesFileExist (path </> "LOCK")
+  when (not dbIsOk) (throwError "Database is missing or corrupted")
+
   version <- withDB path (\db -> L.get db def "version")
-  when (version /= Just "1") (throwError "Unsupported schema version")
+  when (version /= Just "1") (throwError "Database is empty or the schema unsupported")
 
   withDB path $ \db -> do
     -- map of id -> isBad