diff --git a/.github/workflows/Test.yml b/.github/workflows/Test.yml
index d769ab27..f9b50928 100644
--- a/.github/workflows/Test.yml
+++ b/.github/workflows/Test.yml
@@ -9,11 +9,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: ocaml/setup-ocaml@v2
-        with:
-          ocaml-compiler: 5.1.1
-      - run: opam install dune
-      - run: opam exec -- dune build
-      - run: opam exec -- dune install
-      - run: eval $(opam env) && ./test.sh dbl ./test/test_suite
-
+      - name: Install Nix
+        uses: cachix/install-nix-action@v17
+      - run: nix shell . --command ./test.sh dbl ./test/test_suite
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 00000000..de1b9d0f
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,267 @@
+{
+  "nodes": {
+    "cpspg": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "cpspg",
+          "opam-nix",
+          "nixpkgs"
+        ],
+        "opam-nix": [
+          "opam-nix"
+        ]
+      },
+      "locked": {
+        "lastModified": 1734182177,
+        "narHash": "sha256-b2pWUouugPrt8Ra5QoB+jhVwZeIgNTjfVRFv9Im7G2Q=",
+        "owner": "Brychlikov",
+        "repo": "cpspg",
+        "rev": "ab0a8575683e4eb75100c137ea76a3e01962b365",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Brychlikov",
+        "repo": "cpspg",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1696426674,
+        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_3": {
+      "inputs": {
+        "systems": "systems_3"
+      },
+      "locked": {
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "mirage-opam-overlays": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1710922379,
+        "narHash": "sha256-j4QREQDUf8oHOX7qg6wAOupgsNQoYlufxoPrgagD+pY=",
+        "owner": "dune-universe",
+        "repo": "mirage-opam-overlays",
+        "rev": "797cb363df3ff763c43c8fbec5cd44de2878757e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "dune-universe",
+        "repo": "mirage-opam-overlays",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1730785428,
+        "narHash": "sha256-Zwl8YgTVJTEum+L+0zVAWvXAGbWAuXHax3KzuejaDyo=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "4aa36568d413aca0ea84a1684d2d46f55dbabad7",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "opam-nix": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils_3",
+        "mirage-opam-overlays": "mirage-opam-overlays",
+        "nixpkgs": "nixpkgs",
+        "opam-overlays": "opam-overlays",
+        "opam-repository": "opam-repository",
+        "opam2json": "opam2json"
+      },
+      "locked": {
+        "lastModified": 1733921344,
+        "narHash": "sha256-D4BFlu5VQCugO6wlze3BxDz5fkxoZishQTIwITLdSw8=",
+        "owner": "tweag",
+        "repo": "opam-nix",
+        "rev": "43ec9805677c7ca3decd57f034c9a148bad5215c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "tweag",
+        "repo": "opam-nix",
+        "type": "github"
+      }
+    },
+    "opam-overlays": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1726822209,
+        "narHash": "sha256-bwM18ydNT9fYq91xfn4gmS21q322NYrKwfq0ldG9GYw=",
+        "owner": "dune-universe",
+        "repo": "opam-overlays",
+        "rev": "f2bec38beca4aea9e481f2fd3ee319c519124649",
+        "type": "github"
+      },
+      "original": {
+        "owner": "dune-universe",
+        "repo": "opam-overlays",
+        "type": "github"
+      }
+    },
+    "opam-repository": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1732612513,
+        "narHash": "sha256-kju4NWEQo4xTxnKeBIsmqnyxIcCg6sNZYJ1FmG/gCDw=",
+        "owner": "ocaml",
+        "repo": "opam-repository",
+        "rev": "3d52b66b04788999a23f22f0d59c2dfc831c4f32",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ocaml",
+        "repo": "opam-repository",
+        "type": "github"
+      }
+    },
+    "opam2json": {
+      "inputs": {
+        "nixpkgs": [
+          "opam-nix",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1671540003,
+        "narHash": "sha256-5pXfbUfpVABtKbii6aaI2EdAZTjHJ2QntEf0QD2O5AM=",
+        "owner": "tweag",
+        "repo": "opam2json",
+        "rev": "819d291ea95e271b0e6027679de6abb4d4f7f680",
+        "type": "github"
+      },
+      "original": {
+        "owner": "tweag",
+        "repo": "opam2json",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "cpspg": "cpspg",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": [
+          "opam-nix",
+          "nixpkgs"
+        ],
+        "opam-nix": "opam-nix"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "systems_3": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 00000000..78607624
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,45 @@
+{
+  inputs = {
+    opam-nix.url = "github:tweag/opam-nix";
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.follows = "opam-nix/nixpkgs";
+    cpspg.url = "github:adampsz/cpspg";
+    cpspg.inputs.opam-nix.follows = "opam-nix";
+  };
+  outputs = { self, flake-utils, opam-nix, nixpkgs, cpspg }@inputs:
+    let package = "dbl";
+    in flake-utils.lib.eachSystem ["x86_64-linux"] (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        on = opam-nix.lib.${system};
+        scope =
+          on.buildDuneProject { } package ./. { ocaml-system = "*"; };
+        overlay = final: prev:
+          {
+            ${package} = prev.${package}.overrideAttrs 
+              (oa: { nativeBuildInputs = oa.nativeBuildInputs ++ [ cpspg.packages.${system}.default ]; });
+          };
+      in rec {
+        legacyPackages = scope.overrideScope overlay;
+
+        packages.default = self.legacyPackages.${system}.${package};
+        devShells.default = with pkgs; pkgs.mkShell {
+          buildInputs = [ 
+              cpspg.packages.${system}.default
+              # Source file formatting
+              nixpkgs-fmt
+              ocamlformat
+              # For `dune build --watch ...`
+              fswatch
+              # For `dune build @doc`
+              ocamlPackages.odoc
+              # OCaml editor support
+              ocamlPackages.ocaml-lsp
+              # Nicely formatted types on hover
+              ocamlPackages.ocamlformat-rpc-lib
+              # Fancy REPL thing
+              ocamlPackages.utop
+          ];
+        };
+      });
+}
diff --git a/src/DblParser/YaccParser.mly b/src/DblParser/YaccParser.mly
index 834432f0..dcd59bf2 100644
--- a/src/DblParser/YaccParser.mly
+++ b/src/DblParser/YaccParser.mly
@@ -145,7 +145,7 @@ op
 | op_80  { $1 }
 | op_90  { $1 }
 | op_100 { $1 }
-; 
+;
 
 /* ========================================================================= */
 
@@ -391,7 +391,7 @@ expr_90
 ;
 
 // exp1 ** exp2
-expr_100 
+expr_100
 : expr_150 op_100 expr_100 { make (EBOp($1, $2, $3)) }
 | expr_150 { $1 }
 ;
@@ -417,6 +417,7 @@ expr_select
 : UID DOT expr_ctor   { (NPName $1, $3) }
 | UID DOT expr_300    { (NPName $1, $3) }
 | UID DOT expr_select { let (p, e) = $3 in (NPSel($1, p), e) }
+;
 
 expr_250
 : expr_300    { $1 }
diff --git a/src/DblParser/dune b/src/DblParser/dune
index 852ef18b..c43de9a1 100644
--- a/src/DblParser/dune
+++ b/src/DblParser/dune
@@ -1,5 +1,10 @@
-(ocamlyacc (modules YaccParser))
 (ocamllex  (modules Lexer))
+;(ocamlyacc (modules YaccParser));
+
+(rule
+ (deps YaccParser.mly)
+ (targets YaccParser.ml YaccParser.mli)
+ (action (chdir %{workspace_root} (run cpspg --compat %{deps} %{targets}))))
 
 (library
   (name dblParser)
diff --git a/test.sh b/test.sh
index 4a01e654..721cf6ed 100755
--- a/test.sh
+++ b/test.sh
@@ -1,18 +1,18 @@
 #!/usr/bin/env bash
 if ! [ -n "$1" ] || ! [ -n "$2" ]; then
-	echo "USAGE: ./test.sh PROGRAM TEST_SUITE"
+	echo "USAGE: ./test.sh BINARY TEST_SUITE"
 	exit 1
 fi
 
-if ! dune build; then
-	exit 1
-fi
+# if ! dune build; then
+# 	exit 1
+# fi
 
 export DBL_LIB="lib/"
 
 TIMEOUT=1.0
 
-binary="_build/default/src/$1.exe"
+binary=$1
 flags=""
 
 RED='\033[0;31m'