diff --git a/tools/v8_gypfiles/features.gypi b/tools/v8_gypfiles/features.gypi
index 7e71e9c46790ab..8b3b0893e5f545 100644
--- a/tools/v8_gypfiles/features.gypi
+++ b/tools/v8_gypfiles/features.gypi
@@ -111,6 +111,17 @@
     # Sets -dENABLE_HUGEPAGE
     'v8_enable_hugepage%': 0,
 
+    # Sets -dV8_ENABLE_PRIVATE_MAPPING_FORK_OPTIMIZATION.
+    #
+    # This flag speeds up the performance of fork/execve on Linux systems for
+    # embedders which use it (like Node.js). It works by marking the pages that
+    # V8 allocates as MADV_DONTFORK. Without MADV_DONTFORK, the Linux kernel
+    # spends a long time manipulating page mappings on fork and exec which the
+    # child process doesn't generally need to access.
+    #
+    # See v8:7381 for more details.
+    'v8_enable_private_mapping_fork_optimization%': 1,
+
     # Sets -dENABLE_VTUNE_JIT_INTERFACE.
     'v8_enable_vtunejit%': 0,
 
@@ -320,6 +331,9 @@
       ['v8_enable_hugepage==1', {
         'defines': ['ENABLE_HUGEPAGE',],
       }],
+      ['v8_enable_private_mapping_fork_optimization==1', {
+        'defines': ['V8_ENABLE_PRIVATE_MAPPING_FORK_OPTIMIZATION'],
+      }],
       ['v8_enable_vtunejit==1', {
         'defines': ['ENABLE_VTUNE_JIT_INTERFACE',],
       }],