diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 5cd1ca50723..af102d8fefc 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -1729,7 +1729,7 @@ self : let callPackage = x : y : modifyPrio (newScope self x y); in
   parsers_0_10_3 = callPackage ../development/libraries/haskell/parsers/0.10.3.nix {};
   parsers_0_11_0_3 = callPackage ../development/libraries/haskell/parsers/0.11.0.3.nix {};
   parsers_0_12 = callPackage ../development/libraries/haskell/parsers/0.12.nix {};
-  parsers = self.parsers_0_12;
+  parsers = self.parsers_0_11_0_3; # the new version breaks trifecta
 
   parsimony = callPackage ../development/libraries/haskell/parsimony {};