diff --git a/.github/workflows/main-stock-ubuntu.yml b/.github/workflows/main-stock-ubuntu.yml
index c5f2665e..f3e74b5f 100644
--- a/.github/workflows/main-stock-ubuntu.yml
+++ b/.github/workflows/main-stock-ubuntu.yml
@@ -116,6 +116,9 @@ jobs:
           echo "::group::xo-reader build"
           cmake --build .build -- xo-reader
 
+          echo "::group::xo-jit build"
+          cmake --build .build -- xo-jit
+
           ##############
 
           echo "::group::xo build (catch all)"
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7bc8c91d..e9a849a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,7 +83,7 @@ add_subdirectory(xo-expression)
 add_subdirectory(xo-pyexpression)
 add_subdirectory(xo-tokenizer)
 add_subdirectory(xo-reader)
-#add_subdirectory(xo-jit)
+add_subdirectory(xo-jit)
 #add_subdirectory(xo-pyjit)
 #add_subdirectory(xo-callback)
 #add_subdirectory(xo-webutil)
diff --git a/default.nix b/default.nix
index 3e2ee09a..938e2d4a 100644
--- a/default.nix
+++ b/default.nix
@@ -57,9 +57,9 @@ let
           xo-tokenizer      = self.callPackage pkgs/xo-tokenizer.nix      {};
           xo-reader         = self.callPackage pkgs/xo-reader.nix         {};
 
-#          xo-jit            = self.callPackage pkgs/xo-jit.nix            { stdenv = customStdenv;
-#                                                                            clang = llvmPackages.clang;
-#                                                                            llvm = llvmPackages.llvm; };
+          xo-jit            = self.callPackage pkgs/xo-jit.nix            { stdenv = customStdenv;
+                                                                            clang = llvmPackages.clang;
+                                                                            llvm = llvmPackages.llvm; };
 #          xo-pyjit          = self.callPackage pkgs/xo-pyjit.nix          {};
 #          xo-callback       = self.callPackage pkgs/xo-callback.nix       {};
 #          xo-webutil        = self.callPackage pkgs/xo-webutil.nix        {};
diff --git a/pkgs/xo-jit.nix b/pkgs/xo-jit.nix
new file mode 100644
index 00000000..0c08bc41
--- /dev/null
+++ b/pkgs/xo-jit.nix
@@ -0,0 +1,37 @@
+{
+  # dependencies
+  stdenv, cmake, catch2,
+  clang, llvm,
+  doxygen,
+
+  python3Packages,
+  sphinx,
+
+  xo-cmake, xo-tokenizer, xo-expression,
+} :
+
+stdenv.mkDerivation (finalattrs:
+  {
+    name = "xo-jit";
+    version = "1.0";
+
+    stdenv = stdenv;
+
+    src = ../xo-jit;
+
+    cmakeFlags = ["-DCMAKE_MODULE_PATH=${xo-cmake}/share/cmake"];
+    doCheck = true;
+    nativeBuildInputs = [
+      cmake
+      catch2
+      clang
+      llvm.dev
+      doxygen
+      sphinx
+      xo-cmake
+      xo-tokenizer
+    ];
+    propagatedBuildInputs = [
+      xo-expression
+    ];
+  })
diff --git a/pkgs/xo-userenv.nix b/pkgs/xo-userenv.nix
index 7ecb7a90..bc3fb0fc 100644
--- a/pkgs/xo-userenv.nix
+++ b/pkgs/xo-userenv.nix
@@ -52,7 +52,7 @@
   xo-pyexpression,
   xo-tokenizer,
   xo-reader,
-#  xo-jit,
+  xo-jit,
 #  xo-pyjit
 
   # other args
@@ -81,8 +81,8 @@ buildEnv {
             xo-pyexpression
             xo-tokenizer
             xo-reader
+            xo-jit
 
-#            xo-jit
 #            xo-pyjit
 #            xo-callback
 #            xo-webutil