diff --git a/.changeset/9ba74d74/changes.json b/.changeset/9ba74d74/changes.json
new file mode 100644
index 00000000..42a4dcd5
--- /dev/null
+++ b/.changeset/9ba74d74/changes.json
@@ -0,0 +1,7 @@
+{
+  "releases": [
+    { "name": "extract-react-types", "type": "patch" },
+    { "name": "kind2string", "type": "patch" }
+  ],
+  "dependents": []
+}
diff --git a/.changeset/9ba74d74/changes.md b/.changeset/9ba74d74/changes.md
new file mode 100644
index 00000000..90b5e363
--- /dev/null
+++ b/.changeset/9ba74d74/changes.md
@@ -0,0 +1 @@
+- Add converter for typeCastExpression
\ No newline at end of file
diff --git a/packages/extract-react-types/__snapshots__/test.js.snap b/packages/extract-react-types/__snapshots__/test.js.snap
index 88868c2b..9ea1e2d9 100644
--- a/packages/extract-react-types/__snapshots__/test.js.snap
+++ b/packages/extract-react-types/__snapshots__/test.js.snap
@@ -169,6 +169,45 @@ Object {
 }
 `;
 
+exports[`Flow TypeCastExpression 1`] = `
+Object {
+  "component": Object {
+    "kind": "generic",
+    "name": Object {
+      "kind": "id",
+      "name": "Component",
+      "type": null,
+    },
+    "value": Object {
+      "kind": "object",
+      "members": Array [
+        Object {
+          "default": Object {
+            "expression": Object {
+              "kind": "id",
+              "name": "ascii",
+              "type": null,
+            },
+            "kind": "typeCastExpression",
+          },
+          "key": Object {
+            "kind": "id",
+            "name": "bar",
+          },
+          "kind": "property",
+          "optional": false,
+          "value": Object {
+            "kind": "string",
+          },
+        },
+      ],
+      "referenceIdName": "Props",
+    },
+  },
+  "kind": "program",
+}
+`;
+
 exports[`NullLiteralTypeAnnotation 1`] = `
 Object {
   "component": Object {
diff --git a/packages/extract-react-types/src/index.js b/packages/extract-react-types/src/index.js
index 693b6611..edcd99f4 100644
--- a/packages/extract-react-types/src/index.js
+++ b/packages/extract-react-types/src/index.js
@@ -417,6 +417,10 @@ converters.StringLiteral = (path, context) /*: K.String*/ => {
   return { kind: 'string', value: path.node.value };
 };
 
+converters.TypeCastExpression = (path, context) /*: K.TypeCastExpression*/ => {
+  return { kind: 'typeCastExpression', expression: convert(path.get('expression'), context) };
+};
+
 /* eslint-disable-next-line no-unused-vars */
 converters.NumericLiteral = (path, context) /*: K.Number*/ => {
   return { kind: 'number', value: path.node.value };
diff --git a/packages/extract-react-types/src/kinds.js b/packages/extract-react-types/src/kinds.js
index 800698bc..49c50ce9 100644
--- a/packages/extract-react-types/src/kinds.js
+++ b/packages/extract-react-types/src/kinds.js
@@ -22,6 +22,10 @@ export type Rest = {
   kind: "rest",
   argument: Id
 };
+export type TypeCastExpression = {
+  kind: "typeCastExpression",
+  expression: Id
+};
 export type TemplateExpression = { kind: "templateExpression", tag: Id };
 export type AssignmentPattern = {
   kind: "assignmentPattern",
diff --git a/packages/extract-react-types/test.js b/packages/extract-react-types/test.js
index 4ff730ba..285bd9f1 100644
--- a/packages/extract-react-types/test.js
+++ b/packages/extract-react-types/test.js
@@ -1545,6 +1545,19 @@ const TESTS = [
 
     }))
     `
+  },
+  {
+    name: 'Flow TypeCastExpression',
+    typeSystem: 'flow',
+    code: `
+    type Props = { bar: string }
+  
+    class Component extends React.Component<Props> {
+      static defaultProps = {
+        bar: (ascii: string),
+      }
+    }
+    `
   }
 ];
 
diff --git a/packages/kind2string/src/index.js b/packages/kind2string/src/index.js
index 2be21ab8..51e6ca32 100644
--- a/packages/kind2string/src/index.js
+++ b/packages/kind2string/src/index.js
@@ -76,7 +76,9 @@ const converters = {
   id: (type /*: K.Id*/, mode /*: string */) /*:string*/ => {
     return type.name;
   },
-
+  typeCastExpression: (type /*: K.TypeCastExpression*/, mode /*: string */) /*:string*/ => {
+    return convert(type.expression);
+  },
   JSXMemberExpression: (type /*:any*/, mode /*: string */) /*:string*/ => {
     return `${convert(type.object)}.${convert(type.property)}`;
   },
diff --git a/packages/kind2string/test.js b/packages/kind2string/test.js
index e98a8f29..8b4005d1 100644
--- a/packages/kind2string/test.js
+++ b/packages/kind2string/test.js
@@ -336,6 +336,20 @@ describe('kind 2 string tests', () => {
       expect(converted).toBe('foo');
     });
   });
+  describe('typecastExpression', () => {
+    let file = `
+    type Props = { bar: string }
+  
+    class Component extends React.Component<Props> {
+      static defaultProps = {
+        bar: (ascii: string),
+      }
+    }
+    `;
+    let res = extractReactTypes(file, 'flow').component.value.members[0].default;
+    let converted = convert(res);
+    expect(converted).toBe('ascii');
+  });
   describe('utilities', () => {
     describe('resolveLast', () => {});
   });