diff --git a/deps/v8/gypfiles/inspector.gypi b/deps/v8/gypfiles/inspector.gypi
index 25d5adf5c2f113..cd90b14c2ede33 100644
--- a/deps/v8/gypfiles/inspector.gypi
+++ b/deps/v8/gypfiles/inspector.gypi
@@ -90,7 +90,7 @@
     {
       'action_name': 'protocol_compatibility',
       'inputs': [
-        '<(inspector_path)/js_protocol.json',
+        '<(inspector_path)/js_protocol.pdl',
       ],
       'outputs': [
         '<@(SHARED_INTERMEDIATE_DIR)/src/js_protocol.stamp',
@@ -99,14 +99,14 @@
         'python',
         '<(protocol_path)/check_protocol_compatibility.py',
         '--stamp', '<@(_outputs)',
-        '<(inspector_path)/js_protocol.json',
+        '<@(_inputs)',
       ],
       'message': 'Checking inspector protocol compatibility',
     },
     {
       'action_name': 'protocol_generated_sources',
       'inputs': [
-        '<(inspector_path)/js_protocol.json',
+        '<(inspector_path)/js_protocol.pdl',
         '<(inspector_path)/inspector_protocol_config.json',
         '<@(inspector_protocol_files)',
       ],
diff --git a/deps/v8/gypfiles/v8.gyp b/deps/v8/gypfiles/v8.gyp
index 458e6f2bf9f1fd..eb31d7087ea35c 100644
--- a/deps/v8/gypfiles/v8.gyp
+++ b/deps/v8/gypfiles/v8.gyp
@@ -8,6 +8,7 @@
     'v8_random_seed%': 314159265,
     'v8_vector_stores%': 0,
     'v8_embed_script%': "",
+    # Placeholder. For upstream V8, this includes test files that Node.js does not need.
     'v8_extra_library_files%': [],
     'mksnapshot_exec': '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)mksnapshot<(EXECUTABLE_SUFFIX)',
     'v8_os_page_size%': 0,
@@ -418,12 +419,16 @@
           'toolsets': ['host', 'target'],
           'dependencies': [
             'mksnapshot#host',
-            'js2c#host',
+            'js2c_extras#host',   # TODO(refack) get rid of this.
+                                  # This has effectively become a noop for Node.js,
+                                  # but the V8 code still tried to acess the code this generates.
+                                  # Refs: https://github.com/nodejs/node/blob/169b7f1f3b3751289f24678930e6a5731464ebc9/deps/v8/src/bootstrapper.cc#L5172-L5174
           ],
         }, {
           'toolsets': ['target'],
           'dependencies': [
             'mksnapshot',
+            'js2c_extras',
           ],
         }],
         ['component=="shared_library"', {
@@ -538,10 +543,10 @@
       'conditions': [
         ['want_separate_host_toolset==1', {
           'toolsets': ['host', 'target'],
-          'dependencies': ['js2c#host'],
+          'dependencies': [ 'js2c_extras#host', ],
         }, {
           'toolsets': ['target'],
-          'dependencies': ['js2c#target'],
+          'dependencies': [ 'js2c_extras', ],
         }],
         ['component=="shared_library"', {
           'defines': [
@@ -2508,7 +2513,7 @@
       },
     }, # v8_libsampler
     {
-      'target_name': 'js2c',
+      'target_name': 'js2c_extras',
       'type': 'none',
       'conditions': [
         ['want_separate_host_toolset==1', {
@@ -2517,14 +2522,6 @@
           'toolsets': ['target'],
         }],
       ],
-      'variables': {
-        'library_files': [
-          '../src/js/macros.py',
-          '../src/message-template.h',
-          '../src/js/prologue.js',
-        ],
-        'libraries_extras_bin_file': '<(SHARED_INTERMEDIATE_DIR)/libraries-extras.bin',
-      },
       'actions': [
        {
           'action_name': 'js2c_extras',
@@ -2535,14 +2532,12 @@
           'outputs': ['<(SHARED_INTERMEDIATE_DIR)/extras-libraries.cc'],
           'action': [
             'python',
-            '../tools/js2c.py',
-            '<(SHARED_INTERMEDIATE_DIR)/extras-libraries.cc',
-            'EXTRAS',
-            '<@(v8_extra_library_files)',
+            '../tools/js2c.py', '<@(_outputs)',
+            'EXTRAS', '<@(v8_extra_library_files)',
           ],
         },
       ],
-    }, # js2c
+    }, # js2c_extras
     {
       'target_name': 'torque_base',
       'type': '<(component)',
diff --git a/deps/v8/gypfiles/v8_external_snapshot.gypi b/deps/v8/gypfiles/v8_external_snapshot.gypi
index bd4ff1017d4ca0..fa6f1916c82886 100644
--- a/deps/v8/gypfiles/v8_external_snapshot.gypi
+++ b/deps/v8/gypfiles/v8_external_snapshot.gypi
@@ -11,7 +11,7 @@
               'toolsets': ['host', 'target'],
               'dependencies': [
                 'mksnapshot#host',
-                'js2c#host',
+                'js2c_extras#host',
                 'natives_blob',
               ]
             }, {
@@ -141,7 +141,7 @@
         ['v8_use_external_startup_data==1', {
           'conditions': [
             ['want_separate_host_toolset==1', {
-              'dependencies': ['js2c#host'],
+              'dependencies': ['js2c_extras#host'],
             }],
           ],
           'actions': [
@@ -151,14 +151,14 @@
                 '../tools/js2c.py',
                 '<@(v8_extra_library_files)',
               ],
-              'outputs': ['<@(libraries_extras_bin_file)'],
+              'outputs': ['<(SHARED_INTERMEDIATE_DIR)/libraries-extras.bin'],
               'action': [
                 'python',
                 '../tools/js2c.py',
                 '<(SHARED_INTERMEDIATE_DIR)/extras-libraries.cc',
                 'EXTRAS',
                 '<@(v8_extra_library_files)',
-                '--startup_blob', '<@(libraries_extras_bin_file)',
+                '--startup_blob', '<@(_outputs)',
                 '--nojs',
               ],
             },