Index: deps/v8/tools/mb/mb.py
--- deps/v8/tools/mb/mb.py.orig
+++ deps/v8/tools/mb/mb.py
@@ -942,7 +942,8 @@ class MetaBuildWrapper():
 
     arch = platform.machine()
     if (arch.startswith('s390') or arch.startswith('ppc') or
-        self.platform.startswith('aix')):
+        self.platform.startswith('aix') or
+        self.platform.startswith('openbsd')):
       # use gn in PATH
       gn_path = 'gn'
     else:
