diff --git a/README.md b/README.md
index c7e1ad3..486b14d 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 
 Get started with:
 
-  git clone https://gn.googlesource.com/gn
-  cd gn
-  build/gen.py
-  ninja -C out
+    git clone https://gn.googlesource.com/gn
+    cd gn
+    build/gen.py
+    ninja -C out
diff --git a/infra/recipes/gn.expected/ci_linux.json b/infra/recipes/gn.expected/ci_linux.json
index 4e5c5ff..8fec41e 100644
--- a/infra/recipes/gn.expected/ci_linux.json
+++ b/infra/recipes/gn.expected/ci_linux.json
@@ -70,18 +70,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]/gn/tools/gn/bootstrap/bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]/gn/build/gen.py"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]/cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]/gn/out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]/cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.expected/ci_mac.json b/infra/recipes/gn.expected/ci_mac.json
index 4e5c5ff..8fec41e 100644
--- a/infra/recipes/gn.expected/ci_mac.json
+++ b/infra/recipes/gn.expected/ci_mac.json
@@ -70,18 +70,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]/gn/tools/gn/bootstrap/bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]/gn/build/gen.py"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]/cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]/gn/out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]/cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.expected/ci_win.json b/infra/recipes/gn.expected/ci_win.json
index 08a77d3..28b0330 100644
--- a/infra/recipes/gn.expected/ci_win.json
+++ b/infra/recipes/gn.expected/ci_win.json
@@ -70,18 +70,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]\\gn\\tools\\gn\\bootstrap\\bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]\\gn\\build\\gen.py"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]\\cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]\\gn\\out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]\\cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.expected/cq_linux.json b/infra/recipes/gn.expected/cq_linux.json
index 306e218..013a468 100644
--- a/infra/recipes/gn.expected/cq_linux.json
+++ b/infra/recipes/gn.expected/cq_linux.json
@@ -97,18 +97,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]/gn/tools/gn/bootstrap/bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]/gn/build/gen.py"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]/cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]/gn/out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]/cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.expected/cq_mac.json b/infra/recipes/gn.expected/cq_mac.json
index 306e218..013a468 100644
--- a/infra/recipes/gn.expected/cq_mac.json
+++ b/infra/recipes/gn.expected/cq_mac.json
@@ -97,18 +97,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]/gn/tools/gn/bootstrap/bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]/gn/build/gen.py"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]/cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]/gn/out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]/cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.expected/cq_win.json b/infra/recipes/gn.expected/cq_win.json
index 124a4a7..83394bd 100644
--- a/infra/recipes/gn.expected/cq_win.json
+++ b/infra/recipes/gn.expected/cq_win.json
@@ -97,18 +97,41 @@
     ]
   },
   {
+    "cmd": [],
+    "name": "build"
+  },
+  {
     "cmd": [
       "python",
       "-u",
-      "[START_DIR]\\gn\\tools\\gn\\bootstrap\\bootstrap.py",
-      "--no-rebuild"
+      "[START_DIR]\\gn\\build\\gen.py"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env_prefixes": {
+      "PATH": [
+        "[START_DIR]\\cipd"
+      ]
+    },
+    "name": "build.generate",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "ninja",
+      "-C",
+      "[START_DIR]\\gn\\out"
     ],
     "env_prefixes": {
       "PATH": [
         "[START_DIR]\\cipd"
       ]
     },
-    "name": "bootstrap"
+    "name": "build.ninja",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@"
+    ]
   },
   {
     "name": "$result",
diff --git a/infra/recipes/gn.py b/infra/recipes/gn.py
index 33012fb..d89466a 100644
--- a/infra/recipes/gn.py
+++ b/infra/recipes/gn.py
@@ -45,11 +45,15 @@
     }
     api.cipd.ensure(cipd_dir, packages)
 
-  with api.context(env_prefixes={'PATH': [cipd_dir]}):
-    api.python(
-        'bootstrap',
-        src_dir.join('tools', 'gn', 'bootstrap', 'bootstrap.py'),
-        args=['--no-rebuild'])
+  with api.step.nest('build'):
+    with api.context(env_prefixes={'PATH': [cipd_dir]}, cwd=src_dir):
+      api.python(
+          'generate',
+          src_dir.join('build', 'gen.py'))
+
+    with api.context(env_prefixes={'PATH': [cipd_dir]}):
+      api.step('ninja',
+              ['ninja', '-C', src_dir.join('out')])
 
 
 def GenTests(api):