diff --git a/flake.lock b/flake.lock
index 4416a7f1f8..6e1a7bcc2f 100644
--- a/flake.lock
+++ b/flake.lock
@@ -31,6 +31,21 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "locked": {
+        "lastModified": 1638122382,
+        "narHash": "sha256-sQzZzAbvKEqN9s0bzWuYmRaA03v40gaJ4+iL1LXjaeI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "74f7e4319258e287b0f9cb95426c9853b282730b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "gitignore": {
       "flake": false,
       "locked": {
@@ -47,6 +62,42 @@
         "type": "github"
       }
     },
+    "lsp-source": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-OcyNHNRh9j5nbJ8SjaNAWIEKuixAJlA7+vTimFY0c2c=",
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-1.4.0.0/lsp-1.4.0.0.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-1.4.0.0/lsp-1.4.0.0.tar.gz"
+      }
+    },
+    "lsp-test-source": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-IOmbQH6tKdu9kAyirvLx6xFS2N+/tbs6vZn0mNGm3No=",
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-test-0.14.0.2/lsp-test-0.14.0.2.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-test-0.14.0.2/lsp-test-0.14.0.2.tar.gz"
+      }
+    },
+    "lsp-types-source": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-K1CeV6o5mmrXubATCh19iFatJ1RtPwpY5lxD8rf/SIw=",
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-types-1.4.0.0/lsp-types-1.4.0.0.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://hackage.haskell.org/package/lsp-types-1.4.0.0/lsp-types-1.4.0.0.tar.gz"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1639357775,
@@ -63,14 +114,24 @@
         "type": "github"
       }
     },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1641016545,
+        "narHash": "sha256-JMNwvnBzG0RjGG3eH27Y5/GlJ9ryeCdGJfqGbqxnmZY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "6f05cfdb1e78d36c0337516df674560e4b51c79b",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
     "pre-commit-hooks": {
       "inputs": {
-        "flake-utils": [
-          "flake-utils"
-        ],
-        "nixpkgs": [
-          "nixpkgs"
-        ]
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_2"
       },
       "locked": {
         "lastModified": 1624971177,
@@ -91,6 +152,9 @@
         "flake-compat": "flake-compat",
         "flake-utils": "flake-utils",
         "gitignore": "gitignore",
+        "lsp-source": "lsp-source",
+        "lsp-test-source": "lsp-test-source",
+        "lsp-types-source": "lsp-types-source",
         "nixpkgs": "nixpkgs",
         "pre-commit-hooks": "pre-commit-hooks"
       }
diff --git a/flake.nix b/flake.nix
index be65c1b420..3b8365f913 100644
--- a/flake.nix
+++ b/flake.nix
@@ -21,9 +21,22 @@
       url = "github:hercules-ci/gitignore.nix";
       flake = false;
     };
+
+    lsp-source = {
+      url = "https://hackage.haskell.org/package/lsp-1.4.0.0/lsp-1.4.0.0.tar.gz";
+      flake = false;
+    };
+    lsp-types-source = {
+      url = "https://hackage.haskell.org/package/lsp-types-1.4.0.0/lsp-types-1.4.0.0.tar.gz";
+      flake = false;
+    };
+    lsp-test-source = {
+      url = "https://hackage.haskell.org/package/lsp-test-0.14.0.2/lsp-test-0.14.0.2.tar.gz";
+      flake = false;
+    };
   };
   outputs =
-    { self, nixpkgs, flake-compat, flake-utils, pre-commit-hooks, gitignore }:
+    { self, nixpkgs, flake-compat, flake-utils, pre-commit-hooks, gitignore, lsp-source, lsp-types-source, lsp-test-source }:
     {
       overlay = final: prev:
         with prev;
@@ -75,6 +88,10 @@
               # We need an older version
               hiedb = hself.hiedb_0_4_1_0;
 
+              lsp = hsuper.callCabal2nix "lsp" lsp-source {};
+              lsp-types = hsuper.callCabal2nix "lsp-types" lsp-types-source {};
+              lsp-test = hsuper.callCabal2nix "lsp-test" lsp-test-source {};
+
               implicit-hie-cradle = hself.callCabal2nix "implicit-hie-cradle"
                 (builtins.fetchTarball {
                   url = "https://hackage.haskell.org/package/implicit-hie-cradle-0.3.0.5/implicit-hie-cradle-0.3.0.5.tar.gz";