Android 6.0 Permission Error

I'm getting this error:

getDeviceId: Neither user 10111 nor current process has android.permission.READ_PHONE_STATE.
   at android.os.Parcel.readException(Parcel.java:1599)
   at android.os.Parcel.readException(Parcel.java:1552)

I had given it in manifest though. Is there any changes regarding Android 6.XX Marshmallow devices? I need to give READ_PHONE_STATE permission for getting device's IMEI. Pls. Help.