diff --git a/packages/opentelemetry-instrumentation-fetch/src/fetch.ts b/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
index d82f6cdc35b..01ff72cb2fa 100644
--- a/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
+++ b/packages/opentelemetry-instrumentation-fetch/src/fetch.ts
@@ -158,6 +158,10 @@ export class FetchInstrumentation extends InstrumentationBase<
       api.propagation.inject(api.context.active(), options.headers, {
         set: (h, k, v) => h.set(k, typeof v === 'string' ? v : String(v)),
       });
+    } else if(options.headers instanceof Headers) {
+      api.propagation.inject(api.context.active(), options.headers, {
+        set: (h, k, v) => h.set(k, typeof v === 'string' ? v : String(v)),
+      });
     } else {
       const headers: Partial<Record<string, unknown>> = {};
       api.propagation.inject(api.context.active(), headers);
diff --git a/packages/opentelemetry-instrumentation-fetch/test/fetch.test.ts b/packages/opentelemetry-instrumentation-fetch/test/fetch.test.ts
index 1fa0d465c7d..1de5b795d0a 100644
--- a/packages/opentelemetry-instrumentation-fetch/test/fetch.test.ts
+++ b/packages/opentelemetry-instrumentation-fetch/test/fetch.test.ts
@@ -535,6 +535,32 @@ describe('fetch', () => {
       assert.ok(typeof r.headers.get(X_B3_TRACE_ID) === 'string');
     });
 
+    it('should keep custom headers with a request object and a headers object', () => {
+      const r = new Request('url', {
+        headers: new Headers({'foo': 'bar'})
+      });
+      window.fetch(r).catch(() => {});
+      assert.ok(r.headers.get('foo') === 'bar');
+    });
+
+    it('should keep custom headers with url, untyped request object and typed headers object', () => {
+      const url = 'url';
+      const init = {
+        headers: new Headers({'foo': 'bar'})
+      };
+      window.fetch(url, init).catch(() => {});
+      assert.ok(init.headers.get('foo') === 'bar');
+    });
+
+    it('should keep custom headers with url, untyped request object and untyped headers object', () => {
+      const url = 'url';
+      const init = {
+        headers: {'foo': 'bar'}
+      };
+      window.fetch(url, init).catch(() => {});
+      assert.ok(init.headers['foo'] === 'bar');
+    });
+
     it('should pass request object as first parameter to the original function (#2411)', () => {
       const r = new Request(url);
       return window.fetch(r).then(() => {
diff --git a/packages/opentelemetry-sdk-trace-base/src/config.ts b/packages/opentelemetry-sdk-trace-base/src/config.ts
index 38c869cfa74..042427d04a0 100644
--- a/packages/opentelemetry-sdk-trace-base/src/config.ts
+++ b/packages/opentelemetry-sdk-trace-base/src/config.ts
@@ -27,6 +27,7 @@ import {
 
 const env = getEnv();
 const FALLBACK_OTEL_TRACES_SAMPLER = TracesSamplerValues.AlwaysOn;
+const DEFAULT_RATIO = 1;
 
 /**
  * Default configuration. For fields with primitive values, any user-provided
@@ -79,8 +80,6 @@ export function buildSamplerFromEnv(
   }
 }
 
-const DEFAULT_RATIO = 1;
-
 function getSamplerProbabilityFromEnv(
   env: Required<ENVIRONMENT>
 ): number | undefined {
diff --git a/website_docs/_index.md b/website_docs/_index.md
index 859f8026cc9..e0846eac64c 100644
--- a/website_docs/_index.md
+++ b/website_docs/_index.md
@@ -1,9 +1,14 @@
 ---
-title: "Javascript"
+title: Javascript
 weight: 20
-description: >
+description: >-
   <img width="35" src="https://raw.github.com/open-telemetry/opentelemetry.io/main/iconography/32x32/JS_SDK.svg"></img>
   A language-specific implementation of OpenTelemetry in JavaScript (for Node.JS & the browser).
+cascade:
+  github_repo: &repo /~https://github.com/open-telemetry/opentelemetry-js
+  github_subdir: website_docs
+  path_base_for_github_subdir: content/en/docs/js/
+  github_project_repo: *repo
 ---
 
 This page contains an introduction to OpenTelemetry in JavaScript. This guide