diff --git a/def/flow.ts b/def/flow.ts
index 7df97cf8..dd5dc2a5 100644
--- a/def/flow.ts
+++ b/def/flow.ts
@@ -171,6 +171,7 @@ export default function (fork: Fork) {
     .field("key", or(def("Literal"), def("Identifier")))
     .field("value", def("FlowType"))
     .field("optional", Boolean)
+    .field("kind", or("init", "get", "set"), () => "init")
     .field("variance", LegacyVariance, defaults["null"]);
 
   def("ObjectTypeIndexer")
diff --git a/gen/builders.ts b/gen/builders.ts
index 3f5254ba..e22db325 100644
--- a/gen/builders.ts
+++ b/gen/builders.ts
@@ -1906,6 +1906,7 @@ export interface ObjectTypePropertyBuilder {
     params: {
       comments?: K.CommentKind[] | null,
       key: K.LiteralKind | K.IdentifierKind,
+      kind?: "init" | "get" | "set",
       loc?: K.SourceLocationKind | null,
       optional: boolean,
       value: K.FlowTypeKind,
diff --git a/gen/namedTypes.ts b/gen/namedTypes.ts
index a520ef45..f1691498 100644
--- a/gen/namedTypes.ts
+++ b/gen/namedTypes.ts
@@ -890,6 +890,7 @@ export namespace namedTypes {
     key: K.LiteralKind | K.IdentifierKind;
     value: K.FlowTypeKind;
     optional: boolean;
+    kind?: "init" | "get" | "set";
     variance?: K.VarianceKind | "plus" | "minus" | null;
   }