diff --git a/.flowconfig b/.flowconfig
index b402919a3..9c7134c36 100644
--- a/.flowconfig
+++ b/.flowconfig
@@ -40,6 +40,8 @@ flow-github/
 [options]
 emoji=true
 
+esproposal.optional_chaining=enable
+
 module.system=haste
 module.system.haste.use_name_reducers=true
 # keep the following in sync with server/haste/hasteImpl.js