diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
index 912935b..6985ea3 100644
--- a/.github/workflows/node.js.yml
+++ b/.github/workflows/node.js.yml
@@ -5,25 +5,25 @@ name: Node.js CI
 
 on:
   push:
-    branches: [ main ]
+    branches: [ main, web_worker_compat ]
   pull_request:
-    branches: [ main ]
+    branches: [ main, web_worker_compat ]
 
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x]
+        node-version: [12.x, 14.x, 15.x]
 
     steps:
-    - uses: actions/checkout@v2
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
-      with:
-        node-version: ${{ matrix.node-version }}
-    - run: npm ci
-    - run: npm run build --if-present
-    - run: npm test
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm run build --if-present
+      - run: npm test
diff --git a/helpers/abortcontroller.js b/helpers/abortcontroller.js
new file mode 100644
index 0000000..844bc16
--- /dev/null
+++ b/helpers/abortcontroller.js
@@ -0,0 +1,21 @@
+'use strict';
+
+class AbortController {
+    constructor() {
+        Object.defineProperty(this, 'signal', { value: {aborted: false}, writable: true, configurable: true });
+    }
+}
+    
+Object.defineProperty(global, 'AbortController', {
+    writable: true,
+    enumerable: false,
+    configurable: true,
+    value: AbortController,
+});
+    
+Object.defineProperty(global, 'self', {
+    writable: true,
+    enumerable: false,
+    configurable: true,
+    value: global,
+});
\ No newline at end of file
diff --git a/jasmine.json b/jasmine.json
index 2f79233..bfdc22d 100644
--- a/jasmine.json
+++ b/jasmine.json
@@ -2,5 +2,8 @@
     "spec_dir": "lib",
     "spec_files": [
         "**/*.spec.js"
+    ],
+    "helpers": [
+      "../helpers/**/*.js"
     ]
 }
diff --git a/src/fetch.spec.ts b/src/fetch.spec.ts
new file mode 100644
index 0000000..b099c5d
--- /dev/null
+++ b/src/fetch.spec.ts
@@ -0,0 +1,29 @@
+import * as fetch from "./fetch";
+
+describe("fetch", () => {
+  describe("fetchEventSource", () => {
+    it("cannot create event source since there is no document", () => {
+      fetch.fetchEventSource("http://localhost:3000", {}).catch((error) => {
+        expect(error).toEqual(new ReferenceError("document is not defined"));
+      });
+    });
+
+    it("cannot create event source since there is no window", () => {
+      fetch
+        .fetchEventSource("http://localhost:3000", { openWhenHidden: true })
+        .catch((error) => {
+          expect(error).toEqual(new ReferenceError("window is not defined"));
+        });
+    });
+
+    it("can create event source", () => {
+      const fetchStub = jasmine.createSpy();
+
+      const promise = fetch.fetchEventSource("http://localhost:3000", {
+        openWhenHidden: true,
+        fetch: fetchStub,
+      });
+      expect(promise).toBeDefined();
+    });
+  });
+});
diff --git a/src/fetch.ts b/src/fetch.ts
index 162ea45..d7aac9d 100644
--- a/src/fetch.ts
+++ b/src/fetch.ts
@@ -86,8 +86,10 @@ export function fetchEventSource(input: RequestInfo, {
         let retryInterval = DefaultRetryInterval;
         let retryTimer = 0;
         function dispose() {
-            document.removeEventListener('visibilitychange', onVisibilityChange);
-            window.clearTimeout(retryTimer);
+            if (!openWhenHidden) {
+                document.removeEventListener('visibilitychange', onVisibilityChange);
+            }
+            self.clearTimeout(retryTimer);
             curRequestController.abort();
         }
 
@@ -131,8 +133,8 @@ export function fetchEventSource(input: RequestInfo, {
                     try {
                         // check if we need to retry:
                         const interval: any = onerror?.(err) ?? retryInterval;
-                        window.clearTimeout(retryTimer);
-                        retryTimer = window.setTimeout(create, interval);
+                        self.clearTimeout(retryTimer);
+                        retryTimer = self.setTimeout(create, interval);
                     } catch (innerErr) {
                         // we should not retry anymore:
                         dispose();