diff --git a/pkgs/development/haskell-modules/configuration-ghc-8.6.x.nix b/pkgs/development/haskell-modules/configuration-ghc-8.6.x.nix
index 1f019c1a582..1f76e8185a5 100644
--- a/pkgs/development/haskell-modules/configuration-ghc-8.6.x.nix
+++ b/pkgs/development/haskell-modules/configuration-ghc-8.6.x.nix
@@ -56,6 +56,7 @@ self: super: {
   hspec = self.hspec_2_5_8;
   hspec-core = self.hspec-core_2_5_8;
   hspec-discover = self.hspec-discover_2_5_8;
+  hspec-megaparsec = doJailbreak super.hspec-megaparsec;  # newer versions need megaparsec 7.x
   hspec-meta = self.hspec-meta_2_5_6;
   JuicyPixels = self.JuicyPixels_3_3_2;
   lens = self.lens_4_17;