diff --git a/doc/languages-frameworks/haskell.section.md b/doc/languages-frameworks/haskell.section.md
index 54ba8e4786d5..733e75c16a79 100644
--- a/doc/languages-frameworks/haskell.section.md
+++ b/doc/languages-frameworks/haskell.section.md
@@ -101,10 +101,10 @@ to compile your Haskell packages with any GHC version you please. The following
 command displays the complete list of available compilers:
 ```
 $ nix-env -f "<nixpkgs>" -qaP -A haskell.compiler
-haskell.compiler.ghc8101                 ghc-8.10.0.20191210
-haskell.compiler.integer-simple.ghc8101  ghc-8.10.0.20191210
-haskell.compiler.ghcHEAD                 ghc-8.10.20191119
-haskell.compiler.integer-simple.ghcHEAD  ghc-8.10.20191119
+haskell.compiler.ghc8101                 ghc-8.10.1
+haskell.compiler.integer-simple.ghc8101  ghc-8.10.1
+haskell.compiler.ghcHEAD                 ghc-8.11.20200403
+haskell.compiler.integer-simple.ghcHEAD  ghc-8.11.20200403
 haskell.compiler.ghc822Binary            ghc-8.2.2-binary
 haskell.compiler.ghc844                  ghc-8.4.4
 haskell.compiler.ghc863Binary            ghc-8.6.3-binary
diff --git a/pkgs/development/compilers/ghc/head.nix b/pkgs/development/compilers/ghc/head.nix
index be8fd73a6be0..d7fe37d1103f 100644
--- a/pkgs/development/compilers/ghc/head.nix
+++ b/pkgs/development/compilers/ghc/head.nix
@@ -2,13 +2,17 @@
 
 # build-tools
 , bootPkgs
-, autoconf, autoreconfHook, automake, coreutils, fetchgit, fetchpatch, perl, python3, m4, sphinx
+, autoconf, autoreconfHook, automake, coreutils, fetchgit, perl, python3, m4, sphinx
 , bash
 
 , libiconv ? null, ncurses
 
+, # GHC can be built with system libffi or a bundled one.
+  libffi ? null
+
 , enableDwarf ? !stdenv.targetPlatform.isDarwin &&
-                !stdenv.targetPlatform.isWindows, elfutils # for DWARF support
+                !stdenv.targetPlatform.isWindows
+, elfutils # for DWARF support
 
 , useLLVM ? !stdenv.targetPlatform.isx86 || stdenv.targetPlatform.isiOS
 , # LLVM is conceptually a run-time-only depedendency, but for
@@ -18,7 +22,8 @@
 
 , # If enabled, GHC will be built with the GPL-free but slower integer-simple
   # library instead of the faster but GPLed integer-gmp library.
-  enableIntegerSimple ? !(stdenv.lib.any (stdenv.lib.meta.platformMatch stdenv.hostPlatform) gmp.meta.platforms), gmp
+  enableIntegerSimple ? !(stdenv.lib.any (stdenv.lib.meta.platformMatch stdenv.hostPlatform) gmp.meta.platforms)
+, gmp
 
 , # If enabled, use -fPIC when compiling static libs.
   enableRelocatedStaticLibs ? stdenv.targetPlatform != stdenv.hostPlatform
@@ -30,7 +35,7 @@
 , # Whetherto build terminfo.
   enableTerminfo ? !stdenv.targetPlatform.isWindows
 
-, version ? "8.10.20191119"
+, version ? "8.11.20200403"
 , # What flavour to build. An empty string indicates no
   # specific flavour and falls back to ghc default values.
   ghcFlavour ? stdenv.lib.optionalString (stdenv.targetPlatform != stdenv.hostPlatform)
@@ -75,6 +80,7 @@ let
 
   # Splicer will pull out correct variations
   libDeps = platform: stdenv.lib.optional enableTerminfo ncurses
+    ++ [libffi]
     ++ stdenv.lib.optional (!enableIntegerSimple) gmp
     ++ stdenv.lib.optional (platform.libc != "glibc" && !targetPlatform.isWindows) libiconv
     ++ stdenv.lib.optional enableDwarf elfutils;
@@ -97,17 +103,14 @@ stdenv.mkDerivation (rec {
 
   src = fetchgit {
     url = "https://gitlab.haskell.org/ghc/ghc.git/";
-    rev = "0418c38d55c7a47967187dce2db5ea2ab1021b1e";
-    sha256 = "1d8g30ii0w4xh6fh61bxbalsqqyanny99nn3p727fx7favnhgvxi";
+    rev = "4291bddaea3148908c55f235ee8978e1d9aa6f20";
+    sha256 = "1gs3mxmsdpsgsp7vnawx8mys0qwg4x2zhfrbciy3wv8nv13ar1af";
   };
 
   enableParallelBuilding = true;
 
   outputs = [ "out" "doc" ];
 
-  patches = [
-  ];
-
   postPatch = "patchShebangs .";
 
   # GHC is a bit confused on its cross terminology.
@@ -130,8 +133,8 @@ stdenv.mkDerivation (rec {
     export STRIP="${targetCC.bintools.bintools}/bin/${targetCC.bintools.targetPrefix}strip"
 
     echo -n "${buildMK}" > mk/build.mk
-    echo ${version} >VERSION
-    echo ${src.rev} >GIT_COMMIT_ID
+    echo ${version} > VERSION
+    echo ${src.rev} > GIT_COMMIT_ID
     ./boot
     sed -i -e 's|-isysroot /Developer/SDKs/MacOSX10.5.sdk||' configure
   '' + stdenv.lib.optionalString (!stdenv.isDarwin) ''
@@ -161,31 +164,40 @@ stdenv.mkDerivation (rec {
   # TODO(@Ericson2314): Always pass "--target" and always prefix.
   configurePlatforms = [ "build" "host" ]
     ++ stdenv.lib.optional (targetPlatform != hostPlatform) "target";
+
   # `--with` flags for libraries needed for RTS linker
   configureFlags = [
     "--datadir=$doc/share/doc/ghc"
-    "--with-curses-includes=${ncurses.dev}/include" "--with-curses-libraries=${ncurses.out}/lib"
+    "--with-curses-libraries=${ncurses.out}/lib"
+  ] ++ stdenv.lib.optionals (libffi != null) [
+    "--with-system-libffi"
+    "--with-ffi-includes=${targetPackages.libffi.dev}/include"
+    "--with-ffi-libraries=${targetPackages.libffi.out}/lib"
   ] ++ stdenv.lib.optionals (targetPlatform == hostPlatform && !enableIntegerSimple) [
-    "--with-gmp-includes=${targetPackages.gmp.dev}/include" "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
+    "--with-gmp-includes=${targetPackages.gmp.dev}/include"
+    "--with-gmp-libraries=${targetPackages.gmp.out}/lib"
   ] ++ stdenv.lib.optionals (targetPlatform == hostPlatform && hostPlatform.libc != "glibc" && !targetPlatform.isWindows) [
-    "--with-iconv-includes=${libiconv}/include" "--with-iconv-libraries=${libiconv}/lib"
+    "--with-iconv-includes=${libiconv}/include"
+    "--with-iconv-libraries=${libiconv}/lib"
   ] ++ stdenv.lib.optionals (targetPlatform != hostPlatform) [
     "--enable-bootstrap-with-devel-snapshot"
   ] ++ stdenv.lib.optionals useLdGold [
     "CFLAGS=-fuse-ld=gold"
     "CONF_GCC_LINKER_OPTS_STAGE1=-fuse-ld=gold"
     "CONF_GCC_LINKER_OPTS_STAGE2=-fuse-ld=gold"
-  ] ++ stdenv.lib.optionals (disableLargeAddressSpace) [
-    "--disable-large-address-space"
-  ] ++ stdenv.lib.optionals enableDwarf [
+  ] ++ stdenv.lib.optional disableLargeAddressSpace "--disable-large-address-space"
+    ++ stdenv.lib.optionals enableDwarf [
     "--enable-dwarf-unwind"
     "--with-libdw-includes=${stdenv.lib.getDev elfutils}/include"
     "--with-libdw-libraries=${stdenv.lib.getLib elfutils}/lib"
   ];
 
-  # Make sure we never relax`$PATH` and hooks support for compatability.
+  # Make sure we never relax`$PATH` and hooks support for compatibility.
   strictDeps = true;
 
+  # Don’t add -liconv to LDFLAGS automatically so that GHC will add it itself.
+	dontAddExtraLibs = true;
+
   nativeBuildInputs = [
     perl autoconf autoreconfHook automake m4 python3 sphinx
     ghc bootPkgs.alex bootPkgs.happy bootPkgs.hscolour
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index 052b84f269e6..aa7ef02a3886 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -81,10 +81,11 @@ in {
       llvmPackages = pkgs.llvmPackages_9;
     };
     ghcHEAD = callPackage ../development/compilers/ghc/head.nix {
-      bootPkgs = packages.ghc865Binary;
+      bootPkgs = packages.ghc883; # no binary yet
       inherit (buildPackages.python3Packages) sphinx;
-      buildLlvmPackages = buildPackages.llvmPackages_6;
-      llvmPackages = pkgs.llvmPackages_6;
+      buildLlvmPackages = buildPackages.llvmPackages_9;
+      llvmPackages = pkgs.llvmPackages_9;
+      libffi = pkgs.libffi;
     };
     ghcjs = compiler.ghcjs86;
     ghcjs86 = callPackage ../development/compilers/ghcjs-ng {