diff --git a/DESIGN.md b/DESIGN.md
index 6918c60..5952216 100644
--- a/DESIGN.md
+++ b/DESIGN.md
@@ -24,7 +24,7 @@ It also includes recommendations for future implementers.
 
 We set for the following goals (mostly taken from
 [brittany](https://github.com/lspitzner/brittany)):
-* Preserve the meaning of the formatted functions;
+* Preserve the meaning of the formatted functions when no CPP is used;
 * Make reasonable use of screen space;
 * Use linear space and computation time on the size of the input;
 * Preserve comments;
@@ -140,8 +140,10 @@ impossible to guess what they'll be called on.
 
 ### CPP
 
-Formatting a module which uses CPP directives won't be supported. Instead,
-we hope for a solution to replace CPP to do conditional compilation.
+We allow CPP directives in the input, but we forgo the goal to preserve the
+meaning of the formatted functions in that case.
+Instead of supporting CPP better, we hope for a solution to replace CPP to
+do conditional compilation.
 
 There are the following challenges when formatting a module with CPP:
 
@@ -180,14 +182,15 @@ True
 ```
 
 At the time of this writing, formatting this program with Hindent
-produces the same output we would get if the CPP directives were
-considered comments:
+or Ormolu produces the same output we would get if the CPP directives
+were considered comments:
 
 ```
-$ hindent --version
-hindent 5.2.7
+$ ormolu --version
+ormolu 0.0.5.0 HEAD fc64eada5c4da7a5b07d2872e253671b48aec115
+using ghc-lib-parser 8.10.1.20200412
 
-$ hindent test.hs
+$ ormolu --mode inplace test.hs
 
 $ cat test.hs
 {-# LANGUAGE CPP #-}
@@ -227,9 +230,6 @@ to parse Haskell modules. If CPP is replaced with some language
 extension or mechanism to do conditional compilation, all tools
 will benefit from it.
 
-Therefore, CPP won't be supported. If the CPP extension
-is enabled, we should signal an error right away.
-
 ### Printing
 
 Just pretty-printing code (following the approach of Hindent) seems sane. It
diff --git a/README.md b/README.md
index 9b0b4aa..31750f6 100644
--- a/README.md
+++ b/README.md
@@ -116,8 +116,9 @@ independent top-level definitions.
 
 * CPP support is experimental. CPP is virtually impossible to handle
   correctly, so we process them as a sort of unchangeable snippets. This
-  works only in simple cases when CPP conditionals are self-contained. Use
-  Ormolu with CPP at your own risk.
+  works only in simple cases when CPP conditionals surround top-level
+  declarations. See the [CPP][design-cpp] section in the design notes for
+  a discussion of the dangers.
 * Input modules should be parsable by Haddock, which is a bit stricter
   criterion than just being valid Haskell modules.
 * Various minor idempotence issues, most of them are related to comments.
@@ -154,7 +155,7 @@ See [LICENSE.md][license].
 
 Copyright © 2018–present Tweag I/O
 
-[design]: https://github.com/tweag/ormolu/blob/master/DESIGN.md#cpp
+[design-cpp]: https://github.com/tweag/ormolu/blob/master/DESIGN.md#cpp
 [contributing]: https://github.com/tweag/ormolu/blob/master/CONTRIBUTING.md
 [license]: https://github.com/tweag/ormolu/blob/master/LICENSE.md
 [haskell-src-exts]: https://hackage.haskell.org/package/haskell-src-exts