diff --git a/sandwich/src/Test/Sandwich/Formatters/Print/CallStacks.hs b/sandwich/src/Test/Sandwich/Formatters/Print/CallStacks.hs
index f34e1e57..34ff0b10 100644
--- a/sandwich/src/Test/Sandwich/Formatters/Print/CallStacks.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/Print/CallStacks.hs
@@ -1,14 +1,25 @@
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
 
 module Test.Sandwich.Formatters.Print.CallStacks where
 
 import Control.Monad
+import Control.Monad.IO.Class
+import Control.Monad.Reader
 import GHC.Stack
+import System.IO (Handle)
 import Test.Sandwich.Formatters.Print.Color
 import Test.Sandwich.Formatters.Print.Printing
+import Test.Sandwich.Formatters.Print.Types
 
 
+printCallStack :: (
+  MonadReader (PrintFormatter, Int, Handle) m, MonadIO m
+  ) => CallStack -> m ()
 printCallStack cs = forM_ (getCallStack cs) printCallStackLine
 
+printCallStackLine :: (
+  MonadReader (PrintFormatter, Int, Handle) m, MonadIO m
+  ) => (String, SrcLoc) -> m ()
 printCallStackLine (f, (SrcLoc {..})) = do
   pic logFunctionColor f
 
diff --git a/sandwich/src/Test/Sandwich/Formatters/Print/Logs.hs b/sandwich/src/Test/Sandwich/Formatters/Print/Logs.hs
index af9403e7..d446b572 100644
--- a/sandwich/src/Test/Sandwich/Formatters/Print/Logs.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/Print/Logs.hs
@@ -1,4 +1,5 @@
 {-# LANGUAGE CPP #-}
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
 
 module Test.Sandwich.Formatters.Print.Logs where
 
@@ -30,6 +31,9 @@ printLogs runTreeLogs = do
           when (logEntryLevel entry >= logLevel) $ printLogEntry entry
 
 
+printLogEntry :: (
+  MonadReader (PrintFormatter, Int, Handle) m, MonadIO m
+  ) => LogEntry -> m ()
 printLogEntry (LogEntry {..}) = do
   pic logTimestampColor (show logEntryTime)
 
diff --git a/sandwich/src/Test/Sandwich/Formatters/Print/PrintPretty.hs b/sandwich/src/Test/Sandwich/Formatters/Print/PrintPretty.hs
index b0b0be40..51666113 100644
--- a/sandwich/src/Test/Sandwich/Formatters/Print/PrintPretty.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/Print/PrintPretty.hs
@@ -7,6 +7,7 @@ module Test.Sandwich.Formatters.Print.PrintPretty (
 import Control.Monad
 import Control.Monad.IO.Class
 import Control.Monad.Reader
+import Data.Colour
 import qualified Data.List as L
 import System.IO
 import Test.Sandwich.Formatters.Print.Color
@@ -39,10 +40,10 @@ printPretty indentFirst (Rec name tuples) = do
   (if indentFirst then pic else pc) recordNameColor name
   pcn braceColor " {"
   withBumpIndent $
-    forM_ tuples $ \(name, val) -> do
-      pic fieldNameColor name
+    forM_ tuples $ \(name', val) -> do
+      pic fieldNameColor name'
       p " = "
-      withBumpIndent' (L.length name + L.length (" = " :: String)) $ do
+      withBumpIndent' (L.length name' + L.length (" = " :: String)) $ do
         printPretty False val
         p "\n"
   pic braceColor "}"
@@ -67,6 +68,9 @@ printPretty (getPrintFn -> f) (Neg s) = do
     printPretty False s
 
 
+printListWrappedIn :: (
+  MonadReader (PrintFormatter, Int, Handle) m, MonadIO m
+  ) => (String, String) -> Bool -> [Value] -> m ()
 printListWrappedIn (begin, end) (getPrintFn -> f) values | all isSingleLine values = do
   f listBracketColor begin
   sequence_ (L.intercalate [p ", "] [[printPretty False v] | v <- values])
@@ -80,5 +84,8 @@ printListWrappedIn (begin, end) (getPrintFn -> f) values = do
       p "\n"
   pic listBracketColor end
 
+getPrintFn :: (
+  MonadReader (PrintFormatter, Int, Handle) m, MonadIO m
+  ) => Bool -> Colour Float -> String -> m ()
 getPrintFn True = pic
 getPrintFn False = pc
diff --git a/sandwich/src/Test/Sandwich/Formatters/Print/Util.hs b/sandwich/src/Test/Sandwich/Formatters/Print/Util.hs
index a8dde9cc..de8e7c30 100644
--- a/sandwich/src/Test/Sandwich/Formatters/Print/Util.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/Print/Util.hs
@@ -24,11 +24,13 @@ isSingleLine (Quote s) = '\n' `L.notElem` s
 
 isSingleLine _ = True
 
+withBumpIndent :: MonadReader (PrintFormatter, Int, c) m => m b -> m b
 withBumpIndent action = do
   (PrintFormatter {..}, _, _) <- ask
   withBumpIndent' printFormatterIndentSize action
 
+withBumpIndent' :: (MonadReader (a, Int, c) m) => Int -> m b -> m b
 withBumpIndent' n = local (\(pf, indent, h) -> (pf, indent + n, h))
 
-
+fst3 :: (a, b, c) -> a
 fst3 (x, _, _) = x
diff --git a/sandwich/src/Test/Sandwich/Formatters/TerminalUI/CrossPlatform.hs b/sandwich/src/Test/Sandwich/Formatters/TerminalUI/CrossPlatform.hs
index 4a2819ed..58465168 100644
--- a/sandwich/src/Test/Sandwich/Formatters/TerminalUI/CrossPlatform.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/TerminalUI/CrossPlatform.hs
@@ -8,5 +8,6 @@ import Control.Monad
 import System.Process
 
 -- | TODO: report exceptions here
+openFileExplorerFolderPortable :: String -> IO ()
 openFileExplorerFolderPortable folder = do
   void $ readCreateProcessWithExitCode (proc "xdg-open" [folder]) ""
diff --git a/sandwich/src/Test/Sandwich/Formatters/TerminalUI/Keys.hs b/sandwich/src/Test/Sandwich/Formatters/TerminalUI/Keys.hs
index 5030adbe..77ecab1c 100644
--- a/sandwich/src/Test/Sandwich/Formatters/TerminalUI/Keys.hs
+++ b/sandwich/src/Test/Sandwich/Formatters/TerminalUI/Keys.hs
@@ -1,3 +1,4 @@
+{-# OPTIONS_GHC -fno-warn-missing-signatures #-}
 
 module Test.Sandwich.Formatters.TerminalUI.Keys where
 
diff --git a/sandwich/src/Test/Sandwich/Golden/Update.hs b/sandwich/src/Test/Sandwich/Golden/Update.hs
index f4d4d9f4..6cd4b4e3 100644
--- a/sandwich/src/Test/Sandwich/Golden/Update.hs
+++ b/sandwich/src/Test/Sandwich/Golden/Update.hs
@@ -29,7 +29,7 @@ updateGolden (fromMaybe defaultDirGoldenTest -> dir) = do
   putStrLnColor enableColor green "Done!"
 
   where
-    go enableColor dir = listDirectory dir >>= mapM_ (processEntry enableColor)
+    go enableColor dir' = listDirectory dir' >>= mapM_ (processEntry enableColor)
 
     processEntry enableColor (((dir ++ "/") ++) -> entryInDir) = do
       isDir <- doesDirectoryExist entryInDir
@@ -55,9 +55,11 @@ green = SetColor Foreground Dull Green
 red = SetColor Foreground Dull Red
 magenta = SetColor Foreground Dull Magenta
 
+putStrColor :: EnableColor -> SGR -> String -> IO ()
 putStrColor EnableColor color s = bracket_ (setSGR [color]) (setSGR [Reset]) (putStr s)
 putStrColor DisableColor _ s = putStr s
 
+putStrLnColor :: EnableColor -> SGR -> String -> IO ()
 putStrLnColor EnableColor color s = bracket_ (setSGR [color]) (setSGR [Reset]) (putStrLn s)
 putStrLnColor DisableColor _ s = putStrLn s
 
diff --git a/sandwich/src/Test/Sandwich/TH/HasMainFunction.hs b/sandwich/src/Test/Sandwich/TH/HasMainFunction.hs
index 2848ae1d..c1242c8e 100644
--- a/sandwich/src/Test/Sandwich/TH/HasMainFunction.hs
+++ b/sandwich/src/Test/Sandwich/TH/HasMainFunction.hs
@@ -19,6 +19,7 @@ data ShouldWarnOnParseError = WarnOnParseError | NoWarnOnParseError
 
 -- | Use haskell-src-exts to determine if a give Haskell file has an exported main function
 -- Parse with all extensions enabled, which will hopefully parse anything
+fileHasMainFunction :: FilePath -> ShouldWarnOnParseError -> Q Bool
 fileHasMainFunction path shouldWarnOnParseError = runIO (parseFileWithExts [x | x@(EnableExtension _) <- knownExtensions] path) >>= \case
   x@(ParseFailed {}) -> do
     when (shouldWarnOnParseError == WarnOnParseError) $