diff --git a/parser/flow.js b/parser/flow.js
index fa553f5c..1badc759 100644
--- a/parser/flow.js
+++ b/parser/flow.js
@@ -18,6 +18,7 @@ const options = {
   esproposal_decorators: true,
   esproposal_export_star_as: true,
   esproposal_optional_chaining: true,
+  esproposal_nullish_coalescing: true,
   token: true,
   types: true,
 };