diff --git a/src/lib/integrations/audible.service.ts b/src/lib/integrations/audible.service.ts
index b796c78..71529a2 100644
--- a/src/lib/integrations/audible.service.ts
+++ b/src/lib/integrations/audible.service.ts
@@ -677,7 +677,7 @@ export class AudibleService {
         {
           params: { region: audnexusRegion },
           timeout: 10000,
-          headers: { 'User-Agent': 'ReadMeABook/1.0' },
+          headers: { 'User-Agent': RMAB_USER_AGENT },
         },
       );
 
@@ -768,7 +768,7 @@ export class AudibleService {
         {
           params: { region: audnexusRegion },
           timeout: 5000,
-          headers: { 'User-Agent': 'ReadMeABook/1.0' },
+          headers: { 'User-Agent': RMAB_USER_AGENT },
         },
       );
 
diff --git a/src/lib/utils/user-agent.ts b/src/lib/utils/user-agent.ts
index b2876d2..ddcf105 100644
--- a/src/lib/utils/user-agent.ts
+++ b/src/lib/utils/user-agent.ts
@@ -1,3 +1,11 @@
+/**
+ * Component: User-Agent Constant
+ *
+ * Centralized User-Agent string used for all outbound HTTP requests.
+ * Replaces the default `axios/x.y.z` UA, which is rejected by some
+ * indexers (e.g., NZBFinder) as a generic-bot signature.
+ */
+
 import { version } from '../../../package.json';
 
-export const RMAB_USER_AGENT = `rmab/${version}`;
+export const RMAB_USER_AGENT = `ReadMeABook/${version}`;
diff --git a/tests/lib/utils/user-agent.test.ts b/tests/lib/utils/user-agent.test.ts
new file mode 100644
index 0000000..a9c9de0
--- /dev/null
+++ b/tests/lib/utils/user-agent.test.ts
@@ -0,0 +1,13 @@
+import { describe, it, expect } from 'vitest';
+import { RMAB_USER_AGENT } from '@/lib/utils/user-agent';
+
+describe('RMAB_USER_AGENT', () => {
+  it('uses the ReadMeABook/<semver> format', () => {
+    expect(RMAB_USER_AGENT).toMatch(/^ReadMeABook\/\d+\.\d+\.\d+/);
+  });
+
+  it('does not look like a generic bot signature', () => {
+    expect(RMAB_USER_AGENT).not.toMatch(/^axios\//);
+    expect(RMAB_USER_AGENT).not.toMatch(/^rmab\//);
+  });
+});