diff --git a/crates/typescript-tests/src/lib.rs b/crates/typescript-tests/src/lib.rs
index 5336adf4..6c6db10e 100644
--- a/crates/typescript-tests/src/lib.rs
+++ b/crates/typescript-tests/src/lib.rs
@@ -5,4 +5,5 @@ pub mod opt_args_and_ret;
 pub mod optional_fields;
 pub mod simple_fn;
 pub mod simple_struct;
+pub mod typescript_type;
 pub mod web_sys;
diff --git a/crates/typescript-tests/src/typescript_type.rs b/crates/typescript-tests/src/typescript_type.rs
new file mode 100644
index 00000000..38e8742f
--- /dev/null
+++ b/crates/typescript-tests/src/typescript_type.rs
@@ -0,0 +1,37 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(typescript_custom_section)]
+const ITEXT_STYLE: &'static str = r#"
+interface ITextStyle {
+    bold: boolean;
+    italic: boolean;
+    size: number;
+}
+"#;
+
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(typescript_type = "ITextStyle")]
+    pub type ITextStyle;
+}
+
+#[wasm_bindgen]
+#[derive(Default)]
+pub struct TextStyle {
+    pub bold: bool,
+    pub italic: bool,
+    pub size: i32,
+}
+
+#[wasm_bindgen]
+impl TextStyle {
+    #[wasm_bindgen(constructor)]
+    pub fn new(_i: ITextStyle) {
+        // parse JsValue
+    }
+
+    pub fn optional_new(_i: Option<ITextStyle>) -> TextStyle {
+        // parse JsValueo
+        TextStyle::default()
+    }
+}
diff --git a/crates/typescript-tests/src/typescript_type.ts b/crates/typescript-tests/src/typescript_type.ts
new file mode 100644
index 00000000..a05ada63
--- /dev/null
+++ b/crates/typescript-tests/src/typescript_type.ts
@@ -0,0 +1,9 @@
+import * as wbg from '../pkg/typescript_tests';
+
+const style: wbg.TextStyle = new wbg.TextStyle({
+  bold: true,
+  italic: true,
+  size: 42,
+});
+
+const optional_style: wbg.TextStyle = wbg.TextStyle.optional_new();