diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## Fourmolu 0.10.1.0
+
+* Fix bug where using `{-` in a single-line comment would wrongfully escape it ([#265](https://github.com/fourmolu/fourmolu/issues/265))
+* Fix idempotence bug with indented multiline comments ([#273](https://github.com/fourmolu/fourmolu/issues/273))
+
 ## Fourmolu 0.10.0.0
 
 New options:
diff --git a/data/fourmolu/haddock-style/input.hs b/data/fourmolu/haddock-style/input.hs
--- a/data/fourmolu/haddock-style/input.hs
+++ b/data/fourmolu/haddock-style/input.hs
@@ -18,6 +18,11 @@
 -}
 multi2 :: Int
 
+{- | This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 -- | This is a haddock
 --
 -- with two consecutive newlines
@@ -27,3 +32,7 @@
 foo :: Int
 foo = 42
 
+-- | This is a haddock containing another haddock
+--
+-- > {-# LANGUAGE ScopedTypeVariables #-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLine.hs b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLine.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{- | This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {- | This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{- | This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLineCompact.hs b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLineCompact.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLineCompact.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockMultiLineCompact.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{- | This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {- | This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{- | This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockSingleLine.hs b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockSingleLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockSingleLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLine-module=HaddockSingleLine.hs
@@ -19,6 +19,11 @@
 -}
 multi2 :: Int
 
+{- | This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {- | This is a haddock
 
 with two consecutive newlines
@@ -28,3 +33,9 @@
 -}
 foo :: Int
 foo = 42
+
+{- | This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLine.hs b/data/fourmolu/haddock-style/output-HaddockMultiLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLine.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{- | This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {- | This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{- | This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLine.hs b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLine.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{-| This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {-| This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{-| This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLineCompact.hs b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLineCompact.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLineCompact.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockMultiLineCompact.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{-| This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {-| This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{-| This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockSingleLine.hs b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockSingleLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockSingleLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact-module=HaddockSingleLine.hs
@@ -19,6 +19,11 @@
 -}
 multi2 :: Int
 
+{-| This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {-| This is a haddock
 
 with two consecutive newlines
@@ -28,3 +33,9 @@
 -}
 foo :: Int
 foo = 42
+
+{-| This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact.hs b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact.hs
--- a/data/fourmolu/haddock-style/output-HaddockMultiLineCompact.hs
+++ b/data/fourmolu/haddock-style/output-HaddockMultiLineCompact.hs
@@ -20,6 +20,11 @@
 -}
 multi2 :: Int
 
+{-| This is a multiline haddock
+     with indentation
+-}
+multi_indentation :: Int
+
 {-| This is a haddock
 
 with two consecutive newlines
@@ -29,3 +34,9 @@
 -}
 foo :: Int
 foo = 42
+
+{-| This is a haddock containing another haddock
+
+> {\-# LANGUAGE ScopedTypeVariables #-\}
+-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLine.hs b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLine.hs
@@ -18,6 +18,10 @@
 -- function haddock
 multi2 :: Int
 
+-- | This is a multiline haddock
+--      with indentation
+multi_indentation :: Int
+
 -- | This is a haddock
 --
 -- with two consecutive newlines
@@ -26,3 +30,8 @@
 -- https://github.com/fourmolu/fourmolu/issues/172
 foo :: Int
 foo = 42
+
+-- | This is a haddock containing another haddock
+--
+-- > {-# LANGUAGE ScopedTypeVariables #-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLineCompact.hs b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLineCompact.hs
--- a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLineCompact.hs
+++ b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockMultiLineCompact.hs
@@ -18,6 +18,10 @@
 -- function haddock
 multi2 :: Int
 
+-- | This is a multiline haddock
+--      with indentation
+multi_indentation :: Int
+
 -- | This is a haddock
 --
 -- with two consecutive newlines
@@ -26,3 +30,8 @@
 -- https://github.com/fourmolu/fourmolu/issues/172
 foo :: Int
 foo = 42
+
+-- | This is a haddock containing another haddock
+--
+-- > {-# LANGUAGE ScopedTypeVariables #-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockSingleLine.hs b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockSingleLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockSingleLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockSingleLine-module=HaddockSingleLine.hs
@@ -17,6 +17,10 @@
 -- function haddock
 multi2 :: Int
 
+-- | This is a multiline haddock
+--      with indentation
+multi_indentation :: Int
+
 -- | This is a haddock
 --
 -- with two consecutive newlines
@@ -25,3 +29,8 @@
 -- https://github.com/fourmolu/fourmolu/issues/172
 foo :: Int
 foo = 42
+
+-- | This is a haddock containing another haddock
+--
+-- > {-# LANGUAGE ScopedTypeVariables #-}
+haddock_in_haddock :: Int
diff --git a/data/fourmolu/haddock-style/output-HaddockSingleLine.hs b/data/fourmolu/haddock-style/output-HaddockSingleLine.hs
--- a/data/fourmolu/haddock-style/output-HaddockSingleLine.hs
+++ b/data/fourmolu/haddock-style/output-HaddockSingleLine.hs
@@ -17,6 +17,10 @@
 -- function haddock
 multi2 :: Int
 
+-- | This is a multiline haddock
+--      with indentation
+multi_indentation :: Int
+
 -- | This is a haddock
 --
 -- with two consecutive newlines
@@ -25,3 +29,8 @@
 -- https://github.com/fourmolu/fourmolu/issues/172
 foo :: Int
 foo = 42
+
+-- | This is a haddock containing another haddock
+--
+-- > {-# LANGUAGE ScopedTypeVariables #-}
+haddock_in_haddock :: Int
diff --git a/fourmolu.cabal b/fourmolu.cabal
--- a/fourmolu.cabal
+++ b/fourmolu.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               fourmolu
-version:            0.10.0.0
+version:            0.10.1.0
 license:            BSD-3-Clause
 license-file:       LICENSE.md
 maintainer:
diff --git a/src/Ormolu/Diff/ParseResult.hs b/src/Ormolu/Diff/ParseResult.hs
--- a/src/Ormolu/Diff/ParseResult.hs
+++ b/src/Ormolu/Diff/ParseResult.hs
@@ -129,7 +129,7 @@
       case cast str1' :: Maybe HsDocString of
         Nothing -> Different []
         Just str1 ->
-          if splitDocString str0 == splitDocString str1
+          if splitDocString True str0 == splitDocString True str1
             then Same
             else Different []
     forLocated ::
diff --git a/src/Ormolu/Printer/Meat/Common.hs b/src/Ormolu/Printer/Meat/Common.hs
--- a/src/Ormolu/Printer/Meat/Common.hs
+++ b/src/Ormolu/Printer/Meat/Common.hs
@@ -165,7 +165,12 @@
   -- Make sure the Haddock is separated by a newline from other comments.
   when goesAfterComment newline
 
-  let docStringLines = splitDocString $ hsDocString str
+  let shouldEscapeCommentBraces =
+        case poHStyle of
+          HaddockSingleLine -> False
+          HaddockMultiLine -> True
+          HaddockMultiLineCompact -> True
+  let docStringLines = splitDocString shouldEscapeCommentBraces $ hsDocString str
 
   mSrcSpan <- getSrcSpan l
 
diff --git a/src/Ormolu/Utils.hs b/src/Ormolu/Utils.hs
--- a/src/Ormolu/Utils.hs
+++ b/src/Ormolu/Utils.hs
@@ -68,15 +68,15 @@
 
 -- | Split and normalize a doc string. The result is a list of lines that
 -- make up the comment.
-splitDocString :: HsDocString -> [Text]
-splitDocString docStr =
+splitDocString :: Bool -> HsDocString -> [Text]
+splitDocString shouldEscapeCommentBraces docStr =
   case r of
     [] -> [""]
     _ -> r
   where
     r =
       fmap (escapeLeadingDollar . escapeCommentBraces)
-        . dropPaddingSpace
+        . dropPaddingSpace'
         . dropWhileEnd T.null
         . fmap (T.stripEnd . T.pack)
         . lines
@@ -88,6 +88,16 @@
       case T.uncons txt of
         Just ('$', _) -> T.cons '\\' txt
         _ -> txt
+    dropPaddingSpace' =
+      case docStr of
+        -- comments using '--'
+        MultiLineDocString {} -> dropPaddingSpace
+        -- comments using '{-'
+        NestedDocString {} -> \case
+          x : xs | Just (' ', x') <- T.uncons x -> x' : xs
+          xs -> xs
+        -- don't care about generated
+        GeneratedDocString {} -> id
     dropPaddingSpace xs =
       case dropWhile T.null xs of
         [] -> []
@@ -102,7 +112,10 @@
            in if leadingSpace x
                 then dropSpace <$> xs
                 else xs
-    escapeCommentBraces = T.replace "{-" "{\\-" . T.replace "-}" "-\\}"
+    escapeCommentBraces =
+      if shouldEscapeCommentBraces
+        then T.replace "{-" "{\\-" . T.replace "-}" "-\\}"
+        else id
 
 -- | Increment line number in a 'SrcSpan'.
 incSpanLine :: Int -> SrcSpan -> SrcSpan