diff --git a/.changeset/pretty-crabs-scream.md b/.changeset/pretty-crabs-scream.md
new file mode 100644
index 00000000000..530fa380c76
--- /dev/null
+++ b/.changeset/pretty-crabs-scream.md
@@ -0,0 +1,5 @@
+---
+"@clerk/nextjs": patch
+---
+
+Mark internal keyless header function async to comply with Server Actions async requirements
diff --git a/packages/nextjs/src/__tests__/keyless-custom-headers.test.ts b/packages/nextjs/src/__tests__/keyless-custom-headers.test.ts
index 48cc8cb896e..7be75419d7a 100644
--- a/packages/nextjs/src/__tests__/keyless-custom-headers.test.ts
+++ b/packages/nextjs/src/__tests__/keyless-custom-headers.test.ts
@@ -166,7 +166,7 @@ describe('keyless-custom-headers', () => {
   });
 
   describe('formatMetadataHeaders', () => {
-    it('should format complete metadata object with all fields present', () => {
+    it('should format complete metadata object with all fields present', async () => {
       const metadata = {
         nodeVersion: 'v18.17.0',
         nextVersion: 'next-server (v15.4.5)',
@@ -181,7 +181,7 @@ describe('keyless-custom-headers', () => {
         isCI: false,
       };
 
-      const result = formatMetadataHeaders(metadata);
+      const result = await formatMetadataHeaders(metadata);
 
       // Test exact header casing and values
       expect(result.get('Clerk-Node-Version')).toBe('v18.17.0');
@@ -196,7 +196,7 @@ describe('keyless-custom-headers', () => {
       expect(result.get('Clerk-Auth-Status')).toBe('signed-out');
     });
 
-    it('should handle missing optional fields gracefully', () => {
+    it('should handle missing optional fields gracefully', async () => {
       const metadata = {
         userAgent: 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)',
         host: 'localhost:3000',
@@ -208,7 +208,7 @@ describe('keyless-custom-headers', () => {
         // Missing: nodeVersion, nextVersion, npmConfigUserAgent, port
       };
 
-      const result = formatMetadataHeaders(metadata);
+      const result = await formatMetadataHeaders(metadata);
 
       // Test that only present fields are set
       expect(result.get('Clerk-Client-User-Agent')).toBe('Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)');
@@ -225,7 +225,7 @@ describe('keyless-custom-headers', () => {
       expect(result.get('Clerk-Node-Port')).toBeNull();
     });
 
-    it('should handle undefined values for optional fields', () => {
+    it('should handle undefined values for optional fields', async () => {
       const metadata = {
         nodeVersion: undefined,
         nextVersion: undefined,
@@ -240,7 +240,7 @@ describe('keyless-custom-headers', () => {
         isCI: false,
       };
 
-      const result = formatMetadataHeaders(metadata);
+      const result = await formatMetadataHeaders(metadata);
 
       // Test that undefined fields are not set
       expect(result.get('Clerk-Node-Version')).toBeNull();
@@ -257,7 +257,7 @@ describe('keyless-custom-headers', () => {
       expect(result.get('Clerk-Auth-Status')).toBe('test-auth-status');
     });
 
-    it('should handle empty string values', () => {
+    it('should handle empty string values', async () => {
       const metadata = {
         nodeVersion: '',
         nextVersion: '',
@@ -272,7 +272,7 @@ describe('keyless-custom-headers', () => {
         isCI: false,
       };
 
-      const result = formatMetadataHeaders(metadata);
+      const result = await formatMetadataHeaders(metadata);
 
       // Empty strings should not be set as headers
       expect(result.get('Clerk-Node-Version')).toBeNull();
@@ -513,7 +513,7 @@ describe('keyless-custom-headers', () => {
 
     // Collect metadata and format headers
     const metadata = await collectKeylessMetadata();
-    const headers = formatMetadataHeaders(metadata);
+    const headers = await formatMetadataHeaders(metadata);
 
     // Verify the full pipeline works correctly
     expect(headers.get('Clerk-Client-User-Agent')).toBe('Integration-Test-Agent');
diff --git a/packages/nextjs/src/server/keyless-custom-headers.ts b/packages/nextjs/src/server/keyless-custom-headers.ts
index 5e216933843..73ca03837b6 100644
--- a/packages/nextjs/src/server/keyless-custom-headers.ts
+++ b/packages/nextjs/src/server/keyless-custom-headers.ts
@@ -20,7 +20,7 @@ interface MetadataHeaders {
  * Collects metadata from the environment and request headers
  */
 export async function collectKeylessMetadata(): Promise<MetadataHeaders> {
-  const headerStore = await headers(); // eslint-disable-line
+  const headerStore = await headers();
 
   return {
     nodeVersion: process.version,
@@ -99,7 +99,7 @@ function getNextVersion(): string | undefined {
 /**
  * Converts metadata to HTTP headers
  */
-export function formatMetadataHeaders(metadata: MetadataHeaders): Headers {
+export async function formatMetadataHeaders(metadata: MetadataHeaders): Promise<Headers> {
   const headers = new Headers();
 
   if (metadata.nodeVersion) {