diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index 002142965c1..b2f086bb9bd 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -716,10 +716,19 @@ self: super: {
     '';
   });
 
-  # The standard libraries are compiled separately
-  idris = generateOptparseApplicativeCompletion "idris" (
-    doJailbreak (dontCheck super.idris)
-  );
+  # The standard libraries are compiled separately.
+  # The megaparsec-7 override is needed because https://github.com/idris-lang/Idris-dev/issues/4826 declares that
+  # idris1 has no plans to migrate to megaparsec-8.
+  # The idris-lang/Idris-dev#4808 patch is for GHC 8.8 compatibility, and can likely be removed with the next release.
+  idris = generateOptparseApplicativeCompletion "idris" (doJailbreak (dontCheck
+    (appendPatches
+      (super.idris.override { megaparsec = self.megaparsec_7_0_5; }) [
+        (pkgs.fetchpatch {
+          url = "https://github.com/idris-lang/Idris-dev/pull/4808.diff";
+          sha256 = "060ib1rczy34ip8xf3bv1pf28655f6s0bvvij19jhh5dpcr0pf71";
+          excludes = [ ".travis.yml" "Makefile" "appveyor.yml" ];
+        })
+      ])));
 
   # https://github.com/bos/math-functions/issues/25
   math-functions = dontCheck super.math-functions;
diff --git a/pkgs/development/haskell-modules/configuration-hackage2nix.yaml b/pkgs/development/haskell-modules/configuration-hackage2nix.yaml
index 9072d7d7e33..f20ba98f3a4 100644
--- a/pkgs/development/haskell-modules/configuration-hackage2nix.yaml
+++ b/pkgs/development/haskell-modules/configuration-hackage2nix.yaml
@@ -2387,6 +2387,7 @@ extra-packages:
   - inline-c-cpp < 0.2                  # required on GHC 8.0.x
   - lens-labels == 0.1.*                # required for proto-lens-descriptors
   - mainland-pretty == 0.6.2.*          # required for tensorflow-opgen-0.1.0.0
+  - megaparsec >= 7.0.4 && < 8          # required for idris: https://github.com/idris-lang/Idris-dev/issues/4826
   - mtl < 2.2                           # newer versions require transformers > 0.4.x, which we cannot provide in GHC 7.8.x
   - mtl-prelude < 2                     # required for to build postgrest on mtl 2.1.x platforms
   - network == 2.6.3.1                  # newer versions don't compile with GHC 7.4.x and below
@@ -6393,7 +6394,6 @@ broken-packages:
   - identifiers
   - idiii
   - idna2008
-  - idris
   - IDynamic
   - ieee-utils
   - iexcloud
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index 1a9e75a37cd..a394e5c9017 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -137052,8 +137052,6 @@ self: {
        ];
        description = "Functional Programming Language with Dependent Types";
        license = stdenv.lib.licenses.bsd3;
-       hydraPlatforms = stdenv.lib.platforms.none;
-       broken = true;
      }) {inherit (pkgs) gmp;};
 
   "ieee" = callPackage
@@ -162376,6 +162374,27 @@ self: {
        broken = true;
      }) {};
 
+  "megaparsec_7_0_5" = callPackage
+    ({ mkDerivation, base, bytestring, case-insensitive, containers
+     , criterion, deepseq, mtl, parser-combinators, scientific, text
+     , transformers, weigh
+     }:
+     mkDerivation {
+       pname = "megaparsec";
+       version = "7.0.5";
+       sha256 = "0bqx1icbmk8s7wmbcdzsgnlh607c7kzg8l80cp02dxr5valjxp7j";
+       libraryHaskellDepends = [
+         base bytestring case-insensitive containers deepseq mtl
+         parser-combinators scientific text transformers
+       ];
+       benchmarkHaskellDepends = [
+         base containers criterion deepseq text weigh
+       ];
+       description = "Monadic parser combinators";
+       license = stdenv.lib.licenses.bsd2;
+       hydraPlatforms = stdenv.lib.platforms.none;
+     }) {};
+
   "megaparsec" = callPackage
     ({ mkDerivation, base, bytestring, case-insensitive, containers
      , criterion, deepseq, mtl, parser-combinators, scientific, text