diff --git a/src/auth/auth.spec.ts b/src/auth/auth.spec.ts
index 4c4c4b9..72ca920 100644
--- a/src/auth/auth.spec.ts
+++ b/src/auth/auth.spec.ts
@@ -5,6 +5,7 @@ import {
   decodeToken
 } from './auth'
 import { DecodedToken } from '../types'
+import { Logger, LogLevel } from '../logger'
 
 describe('isAccessTokenExpiring', () => {
   it('should return true if the token is expiring in an hour', () => {
@@ -43,6 +44,56 @@ describe('isAccessTokenExpiring', () => {
     ).toBeFalsy()
   })
 
+  it('should route opaque-token debug message through process.logger, not console.debug', () => {
+    const debugSpy = jest.spyOn(console, 'debug').mockImplementation(() => {})
+    const logger = new Logger(LogLevel.Debug)
+    const loggerSpy = jest.spyOn(logger, 'debug').mockImplementation(() => {})
+    const originalLogger = process.logger
+    Object.defineProperty(process, 'logger', {
+      value: logger,
+      configurable: true,
+      writable: true
+    })
+
+    try {
+      isAccessTokenExpiring('1f8da55057bd4f50a6577f0bc2b38b1a-r')
+      expect(loggerSpy).toHaveBeenCalledWith(
+        'isTokenExpiring: token is not a decodable JWT, treating it as not expiring.'
+      )
+      expect(debugSpy).not.toHaveBeenCalled()
+    } finally {
+      Object.defineProperty(process, 'logger', {
+        value: originalLogger,
+        configurable: true,
+        writable: true
+      })
+      debugSpy.mockRestore()
+      loggerSpy.mockRestore()
+    }
+  })
+
+  it('should not call console.debug for an opaque token when no logger is set', () => {
+    const debugSpy = jest.spyOn(console, 'debug').mockImplementation(() => {})
+    const originalLogger = process.logger
+    Object.defineProperty(process, 'logger', {
+      value: undefined,
+      configurable: true,
+      writable: true
+    })
+
+    try {
+      isAccessTokenExpiring('1f8da55057bd4f50a6577f0bc2b38b1a-r')
+      expect(debugSpy).not.toHaveBeenCalled()
+    } finally {
+      Object.defineProperty(process, 'logger', {
+        value: originalLogger,
+        configurable: true,
+        writable: true
+      })
+      debugSpy.mockRestore()
+    }
+  })
+
   it('should return false for a JWT without an exp claim', () => {
     expect(isAccessTokenExpiring(generateTokenWithoutExp())).toBeFalsy()
   })
diff --git a/src/auth/auth.ts b/src/auth/auth.ts
index 5629d4c..14cceb0 100644
--- a/src/auth/auth.ts
+++ b/src/auth/auth.ts
@@ -61,7 +61,10 @@ function isTokenExpiring(token: string, timeToLiveSeconds: number) {
     if (!(err instanceof InvalidTokenError)) throw err
     // Opaque tokens cannot be expiry-checked client-side.
     // Assume the token is usable and let the server reject it if expired.
-    console.debug(
+    // Route through process.logger so the message respects the configured
+    // log level and doesn't pollute stdout in CI/test runs. Falls back to a
+    // no-op when no logger has been installed (e.g. library-only usage).
+    process.logger?.debug?.(
       'isTokenExpiring: token is not a decodable JWT, treating it as not expiring.'
     )
     return false
diff --git a/src/types/system/process.d.ts b/src/types/system/process.d.ts
new file mode 100644
index 0000000..dde24f8
--- /dev/null
+++ b/src/types/system/process.d.ts
@@ -0,0 +1,5 @@
+declare namespace NodeJS {
+  export interface Process {
+    logger?: import('../../logger/logger').Logger
+  }
+}
diff --git a/tsconfig.json b/tsconfig.json
index 1104fcb..58d711d 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -14,5 +14,8 @@
     "sourceMap": true
   },
   "exclude": ["node_modules", "**/*.spec.ts"],
-  "include": ["src"]
+  "include": ["src"],
+  "ts-node": {
+    "files": true
+  }
 }