diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a2d5be1..2c003cd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -167,3 +167,36 @@ jobs:
         id: run_bun
         run: |
           bun --version
+
+  setup-bun-jsr-registry:
+    name: setup-bun jsr registry (${{ matrix.os }})
+    runs-on: ${{ matrix.os }}
+    continue-on-error: true
+    needs: [remove-cache, tests]
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+          - windows-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Bun
+        uses: ./
+        id: setup_bun
+        with:
+          registries: |
+            [
+              {
+                "url": "https://npm.jsr.io"
+                "scope": "@jsr"
+              }
+            ]
+
+      - name: Run Bun
+        id: run_bun
+        run: |
+          bun add @luca/runtime-detector
diff --git a/src/bunfig.ts b/src/bunfig.ts
index 95c246c..8d964f7 100644
--- a/src/bunfig.ts
+++ b/src/bunfig.ts
@@ -5,7 +5,7 @@ import { info } from "@actions/core";
 export type Registry = {
   url: string;
   scope: string;
-  token: string;
+  token?: string;
 };
 
 enum FieldType {
@@ -40,7 +40,9 @@ export function createField(registry: Registry): Field {
   if (url && owner) {
     return {
       type: FieldType.INSTALL_WITH_SCOPE,
-      value: `'${owner}' = { token = "${token}", url = "${url}" }`,
+      value: `'${owner}' = { url = "${url}"${
+        token ? `, token = "${token}"` : ""
+      } }`,
     };
   }
 
diff --git a/tests/bunfig.spec.ts b/tests/bunfig.spec.ts
index 9f52dc7..05f64b6 100644
--- a/tests/bunfig.spec.ts
+++ b/tests/bunfig.spec.ts
@@ -34,7 +34,7 @@ describe("writeBunfig", () => {
 
       const expectedContents = [
         "[install.scopes]",
-        '\'@foo-bar\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
+        '\'@foo-bar\' = { url = "https://npm.pkg.github.com/", token = "$BUN_AUTH_TOKEN" }',
         "",
       ];
 
@@ -97,7 +97,7 @@ describe("writeBunfig", () => {
         "[install.cache]",
         "disable = true",
         "[install.scopes]",
-        '\'@foo-bar\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
+        '\'@foo-bar\' = { url = "https://npm.pkg.github.com/", token = "$BUN_AUTH_TOKEN" }',
         "",
       ];
 
@@ -130,7 +130,7 @@ describe("writeBunfig", () => {
         "optional = true",
         "",
         "[install.scopes]",
-        '\'@foo-bar\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
+        '\'@foo-bar\' = { url = "https://npm.pkg.github.com/", token = "$BUN_AUTH_TOKEN" }',
         '\'@bla-ble\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
         "",
         "[install.cache]",
@@ -167,7 +167,7 @@ describe("writeBunfig", () => {
         "optional = true",
         "",
         "[install.scopes]",
-        '\'@foo-bar\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
+        '\'@foo-bar\' = { url = "https://npm.pkg.github.com/", token = "$BUN_AUTH_TOKEN" }',
         '\'@bla-ble\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
         "",
         "[install.cache]",
@@ -210,7 +210,7 @@ describe("writeBunfig", () => {
         "optional = true",
         "",
         "[install.scopes]",
-        '\'@foo-bar\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
+        '\'@foo-bar\' = { url = "https://npm.pkg.github.com/", token = "$BUN_AUTH_TOKEN" }',
         '\'@bla-ble\' = { token = "$BUN_AUTH_TOKEN", url = "https://npm.pkg.github.com/" }',
         "",
         "[install.cache]",