diff --git a/language-rust.cabal b/language-rust.cabal
index 6871c88..0f30d1a 100644
--- a/language-rust.cabal
+++ b/language-rust.cabal
@@ -41,8 +41,8 @@ library
                        -Wincomplete-uni-patterns
                        -Wmissing-signatures
 
-  build-tools:         alex >=3.1, happy >=1.19.8 && < 2.1
-  -- We restrict to < 2.1, because of
+  build-tools:         alex >=3.1, happy >=1.19.8 && < 2.1 || >= 2.1.1
+  -- We restrict to < 2.1 || >= 2.1.1, because of
   -- https://github.com/haskell/happy/issues/320
 
   default-language:    Haskell2010