Index: Src/GoogleApis.Auth/OAuth2/Responses/TokenResponse.cs
===================================================================
--- a/Src/GoogleApis.Auth/OAuth2/Responses/TokenResponse.cs
+++ b/Src/GoogleApis.Auth/OAuth2/Responses/TokenResponse.cs
@@ -70,7 +70,7 @@
                 return true;
             }
 
-            return Issued.AddSeconds(ExpiresInSeconds.Value + 60) <= clock.Now;
+            return Issued.AddSeconds(ExpiresInSeconds.Value - 60) <= clock.Now;
         }
     }
 }
\ No newline at end of file