diff --git a/ts-rs/src/lib.rs b/ts-rs/src/lib.rs
index afe3ddb21..68509e25c 100644
--- a/ts-rs/src/lib.rs
+++ b/ts-rs/src/lib.rs
@@ -440,11 +440,11 @@ impl<T: TS> TS for Option<T> {
             "called Option::name_with_type_args with {} args",
             args.len()
         );
-        format!("{} | null", args[0])
+        format!("({} | null)", args[0])
     }
 
     fn inline() -> String {
-        format!("{} | null", T::inline())
+        format!("({} | null)", T::inline())
     }
 
     fn dependencies() -> Vec<Dependency>
@@ -471,11 +471,11 @@ impl<T: TS, E: TS> TS for Result<T, E> {
             "called Result::name_with_type_args with {} args",
             args.len()
         );
-        format!("{{ ok: {} }} | {{ err: {} }}", args[0], args[1])
+        format!("({{ ok: {} }} | {{ err: {} }})", args[0], args[1])
     }
 
     fn inline() -> String {
-        format!("{{ ok: {} }} | {{ err: {} }}", T::inline(), E::inline())
+        format!("({{ ok: {} }} | {{ err: {} }})", T::inline(), E::inline())
     }
 
     fn dependencies() -> Vec<Dependency>
diff --git a/ts-rs/tests/optional_field.rs b/ts-rs/tests/optional_field.rs
index 807e9daf1..3f53278fe 100644
--- a/ts-rs/tests/optional_field.rs
+++ b/ts-rs/tests/optional_field.rs
@@ -14,7 +14,7 @@ struct Optional {
 #[test]
 fn test() {
     #[cfg(not(feature = "serde-compat"))]
-    assert_eq!(Optional::inline(), "{ a?: number, b: string | null, }");
+    assert_eq!(Optional::inline(), "({ a?: number, b: string | null, })");
     #[cfg(feature = "serde-compat")]
-    assert_eq!(Optional::inline(), "{ a?: number, b?: string, }")
+    assert_eq!(Optional::inline(), "({ a?: number, b?: string, })")
 }
diff --git a/ts-rs/tests/result.rs b/ts-rs/tests/result.rs
index 65e7ad33f..cd14b7f4f 100644
--- a/ts-rs/tests/result.rs
+++ b/ts-rs/tests/result.rs
@@ -11,6 +11,6 @@ struct Fallible {
 fn test() {
     assert_eq!(
         Fallible::inline(),
-        "{ a: { ok: number } | { err: string }, }"
+        "({ a: { ok: number } | { err: string }, })"
     )
 }