diff --git a/packages/flow-parser/test/custom_ast_types.js b/packages/flow-parser/test/custom_ast_types.js
index c29dc953928..6ce2cd382f4 100644
--- a/packages/flow-parser/test/custom_ast_types.js
+++ b/packages/flow-parser/test/custom_ast_types.js
@@ -249,10 +249,6 @@ function custom_ast_types(fork) {
     .bases('FlowType')
     .build('argument')
     .field('argument', def('FlowType'));
-  def('ReadOnlyTypeAnnotation')
-    .bases('FlowType')
-    .build('argument')
-    .field('argument', def('FlowType'));
   def('TypeParameter').field('usesExtendsBound', or(undefined, Boolean));
   def('Variance').field(
     'kind',
diff --git a/src/parser/estree_translator.ml b/src/parser/estree_translator.ml
index 7f87ab58036..22852c0ce25 100644
--- a/src/parser/estree_translator.ml
+++ b/src/parser/estree_translator.ml
@@ -1958,7 +1958,7 @@ with type t = Impl.t = struct
         loc
         [("operator", string operator); ("typeAnnotation", _type operand)]
     and read_only_type (loc, { Type.ReadOnly.argument; comments }) =
-      node ?comments "ReadOnlyTypeAnnotation" loc [("argument", _type argument)]
+      flow_type_operator loc comments "readonly" argument
     and tuple_type (loc, { Type.Tuple.elements; comments }) =
       node
         ?comments
diff --git a/src/parser/test/flow/ts_syntax/invalid_readonly_type.tree.json b/src/parser/test/flow/ts_syntax/invalid_readonly_type.tree.json
index 426b2a44dd0..4e7233cd844 100644
--- a/src/parser/test/flow/ts_syntax/invalid_readonly_type.tree.json
+++ b/src/parser/test/flow/ts_syntax/invalid_readonly_type.tree.json
@@ -23,10 +23,11 @@
       },
       "typeParameters":null,
       "right":{
-        "type":"ReadOnlyTypeAnnotation",
+        "type":"TypeOperator",
         "loc":{"source":null,"start":{"line":1,"column":9},"end":{"line":1,"column":17}},
         "range":[9,17],
-        "argument":{
+        "operator":"readonly",
+        "typeAnnotation":{
           "type":"AnyTypeAnnotation",
           "loc":{"source":null,"start":{"line":2,"column":0},"end":{"line":2,"column":0}},
           "range":[18,18]
diff --git a/src/parser/test/flow/ts_syntax/readonly_type.tree.json b/src/parser/test/flow/ts_syntax/readonly_type.tree.json
index b19957ffaa2..2fb0392d7d2 100644
--- a/src/parser/test/flow/ts_syntax/readonly_type.tree.json
+++ b/src/parser/test/flow/ts_syntax/readonly_type.tree.json
@@ -17,10 +17,11 @@
       },
       "typeParameters":null,
       "right":{
-        "type":"ReadOnlyTypeAnnotation",
+        "type":"TypeOperator",
         "loc":{"source":null,"start":{"line":1,"column":9},"end":{"line":1,"column":34}},
         "range":[9,34],
-        "argument":{
+        "operator":"readonly",
+        "typeAnnotation":{
           "type":"TupleTypeAnnotation",
           "loc":{"source":null,"start":{"line":1,"column":18},"end":{"line":1,"column":34}},
           "range":[18,34],
@@ -53,10 +54,11 @@
       },
       "typeParameters":null,
       "right":{
-        "type":"ReadOnlyTypeAnnotation",
+        "type":"TypeOperator",
         "loc":{"source":null,"start":{"line":2,"column":9},"end":{"line":2,"column":26}},
         "range":[45,62],
-        "argument":{
+        "operator":"readonly",
+        "typeAnnotation":{
           "type":"ArrayTypeAnnotation",
           "loc":{"source":null,"start":{"line":2,"column":18},"end":{"line":2,"column":26}},
           "range":[54,62],
@@ -82,10 +84,11 @@
       },
       "typeParameters":null,
       "right":{
-        "type":"ReadOnlyTypeAnnotation",
+        "type":"TypeOperator",
         "loc":{"source":null,"start":{"line":3,"column":9},"end":{"line":3,"column":24}},
         "range":[73,88],
-        "argument":{
+        "operator":"readonly",
+        "typeAnnotation":{
           "type":"NumberTypeAnnotation",
           "loc":{"source":null,"start":{"line":3,"column":18},"end":{"line":3,"column":24}},
           "range":[82,88]