diff --git a/Cargo.toml b/Cargo.toml
index d2c1796..4d8aecb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tsify-next"
-version = "0.5.0"
+version = "0.5.1"
 edition = "2021"
 authors = [
   "Madono Haru <madonoharu@gmail.com>",
@@ -14,7 +14,7 @@ keywords = ["wasm", "wasm-bindgen", "typescript"]
 categories = ["wasm"]
 
 [dependencies]
-tsify-next-macros = { path = "tsify-next-macros", version = "^0.5" }
+tsify-next-macros = { path = "tsify-next-macros", version = "0.5.1" }
 wasm-bindgen = { version = "0.2.86", optional = true }
 serde = { version = "1.0", optional = true }
 serde_json = { version = "1.0", optional = true }
diff --git a/tests-e2e/reference_output/test2/test2.d.ts b/tests-e2e/reference_output/test2/test2.d.ts
new file mode 100644
index 0000000..4c996b0
--- /dev/null
+++ b/tests-e2e/reference_output/test2/test2.d.ts
@@ -0,0 +1,13 @@
+/* tslint:disable */
+/* eslint-disable */
+/**
+* @returns {Point}
+*/
+export function into_js(): Point;
+export interface Point {
+    x: number;
+    y: number;
+}
+
+export type NullPoint = void;
+
diff --git a/tests-e2e/test2/Cargo.toml b/tests-e2e/test2/Cargo.toml
new file mode 100644
index 0000000..177ffe8
--- /dev/null
+++ b/tests-e2e/test2/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "test2"
+publish = false
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+wasm-bindgen = "0.2"
+tsify-next = { path = "../..", version = "*" }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3"
+
+[lib]
+path = "entry_point.rs"
+crate-type = ["cdylib"]
+
+[build-dependencies]
+wasm-bindgen-cli = "0.2"
diff --git a/tests-e2e/test2/entry_point.rs b/tests-e2e/test2/entry_point.rs
new file mode 100644
index 0000000..41993ff
--- /dev/null
+++ b/tests-e2e/test2/entry_point.rs
@@ -0,0 +1,19 @@
+use serde::{Deserialize, Serialize};
+use tsify_next::Tsify;
+use wasm_bindgen::prelude::*;
+
+#[derive(Tsify, Serialize, Deserialize)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub struct Point {
+    x: i32,
+    y: i32,
+}
+
+#[derive(Tsify, Serialize, Deserialize)]
+#[tsify(into_wasm_abi, from_wasm_abi)]
+pub enum NullPoint {}
+
+#[wasm_bindgen]
+pub fn into_js() -> Point {
+    Point { x: 0, y: 0 }
+}
diff --git a/tests/enum.rs b/tests/enum.rs
index 83f3159..51a7b19 100644
--- a/tests/enum.rs
+++ b/tests/enum.rs
@@ -38,6 +38,18 @@ fn test_externally_tagged_enum() {
     assert_eq!(External::DECL, expected);
 }
 
+#[test]
+fn test_empty_enum() {
+    #[derive(Tsify)]
+    enum Empty {}
+
+    let expected = indoc! {r#"
+        export type Empty = void;"#
+    };
+
+    assert_eq!(Empty::DECL, expected);
+}
+
 #[test]
 fn test_externally_tagged_enum_with_namespace() {
     /// Comment for External
diff --git a/tsify-next-macros/Cargo.toml b/tsify-next-macros/Cargo.toml
index 22a653b..b3f2fdd 100644
--- a/tsify-next-macros/Cargo.toml
+++ b/tsify-next-macros/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "tsify-next-macros"
-version = "0.5.0"
+version = "0.5.1"
 edition = "2021"
 authors = [
     "Madono Haru <madonoharu@gmail.com>",
diff --git a/tsify-next-macros/src/decl.rs b/tsify-next-macros/src/decl.rs
index de0c69d..26e1288 100644
--- a/tsify-next-macros/src/decl.rs
+++ b/tsify-next-macros/src/decl.rs
@@ -91,6 +91,7 @@ impl Display for TsInterfaceDecl {
     }
 }
 
+/// A Typescript type resulting from an enum declaration.
 #[derive(Debug)]
 pub struct TsEnumDecl {
     pub id: String,
@@ -278,6 +279,8 @@ impl Display for TsEnumDecl {
     }
 }
 
+/// A typescript type declaration. For example `type Foo = string;`
+/// or `interface Bar { baz: number; }`
 #[allow(clippy::enum_variant_names)]
 pub enum Decl {
     TsTypeAlias(TsTypeAliasDecl),
diff --git a/tsify-next-macros/src/derive.rs b/tsify-next-macros/src/derive.rs
index 85bf49d..624c776 100644
--- a/tsify-next-macros/src/derive.rs
+++ b/tsify-next-macros/src/derive.rs
@@ -35,6 +35,7 @@ pub fn expand(input: DeriveInput) -> syn::Result<TokenStream> {
     Ok(tokens)
 }
 
+/// Expand an `enum` or `struct` with `#[derive(Tsify)]`.
 pub fn expand_by_attr(args: TokenStream, input: DeriveInput) -> syn::Result<TokenStream> {
     let mut cloned_input = input.clone();
     let attr: syn::Attribute = parse_quote!(#[tsify(#args)]);
diff --git a/tsify-next-macros/src/typescript/ts_type_display.rs b/tsify-next-macros/src/typescript/ts_type_display.rs
index 64a6938..d0035c0 100644
--- a/tsify-next-macros/src/typescript/ts_type_display.rs
+++ b/tsify-next-macros/src/typescript/ts_type_display.rs
@@ -91,23 +91,27 @@ impl Display for TsType {
                 write!(f, "{types}")
             }
 
-            TsType::Union(types) => {
-                if types.len() == 1 {
+            TsType::Union(types) => match types.len() {
+                0 => {
+                    write!(f, "void")
+                }
+                1 => {
                     let ty = &types[0];
-                    return write!(f, "{ty}");
+                    write!(f, "{ty}")
                 }
-
-                let types = types
-                    .iter()
-                    .map(|ty| match ty {
-                        TsType::Intersection(_) => format!("({ty})"),
-                        _ => ty.to_string(),
-                    })
-                    .collect::<Vec<_>>()
-                    .join(" | ");
-
-                write!(f, "{types}")
-            }
+                _ => {
+                    let types = types
+                        .iter()
+                        .map(|ty| match ty {
+                            TsType::Intersection(_) => format!("({ty})"),
+                            _ => ty.to_string(),
+                        })
+                        .collect::<Vec<_>>()
+                        .join(" | ");
+
+                    write!(f, "{types}")
+                }
+            },
 
             TsType::Override { type_override, .. } => f.write_str(type_override),
         }