diff --git a/.gitignore b/.gitignore
index eede881..d8124e3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,5 @@
 .idea
 .DS_Store
 .project
-.pydevproject
\ No newline at end of file
+.pydevproject
+credentials.py
\ No newline at end of file
diff --git a/README.md b/README.md
index b221029..fbb9110 100644
--- a/README.md
+++ b/README.md
@@ -17,11 +17,24 @@ These are incredibly simple scripts, but do require a few small configurations.
 * If you do not have pip or are running windows, please see [Unofficial Google Music API usage](http://unofficial-google-music-api.readthedocs.org/en/latest/usage.html)
 
 ### Change login credentials
-* Near line 89, change the 'username' and 'password' to your Google account credentials.
+* Near line 12 in the script, change the 'username' and 'password' to your Google account credentials. 
+* Alternatively, create an empty file called 'credentials.py' in the script directory and set the username and password variables there.
+
+```python
+# credentials.py
+username = 'changeme@gmail.com'
+password = 'changeme'
+#android_id = 'deadbeefc0decafe'
+```
+
 * NOTE: Users with 2-step authentication enabled will have to create an App Specific Key/Password.
 Login into your Google account and head to https://security.google.com/settings/security/apppasswords, there you will be able to manually generate an App Specific password.
 After creating the Key/Password, just use it to login into this App, together with your usual Google username/email.
 
+* NOTE: If you see the error message "a valid MAC could not be determined."
+you are running into a [known issue](https://github.com/simon-weber/gmusicapi/issues/408) with the Google Music API.
+To workaround, set a new 16 digit hexadecimal number as your android_id on line 17 or in credentials.py.
+
 ### Run kill_dupes
 * The script will automatically detect and remove duplicates on any songs in your library.
 
diff --git a/kill_dupes b/kill_dupes
index b1c5b4b..504d162 100755
--- a/kill_dupes
+++ b/kill_dupes
@@ -3,6 +3,21 @@ import sys
 
 from gmusicapi import Mobileclient
 
+try:
+    import credentials
+    # credentials.py is in .gitignore and can be shared with other scripts
+    username = credentials.username
+    password = credentials.password
+except ImportError:
+    username = 'username'
+    password = 'password'
+
+try:
+    # optionally hardcode id to workaround https://github.com/simon-weber/gmusicapi/issues/408
+    android_id = credentials.android_id
+except (NameError, AttributeError):
+    android_id = Mobileclient.FROM_MAC_ADDRESS
+
 
 def map_track_duplication(tracks):
     album_track_duplicate_map = {}
@@ -109,7 +124,7 @@ def get_track_ids(tracks):
 
 
 api = Mobileclient()
-logged_in = api.login('username', 'password', Mobileclient.FROM_MAC_ADDRESS)
+logged_in = api.login(username, password, android_id)
 
 if logged_in:
     print("Successfully logged in. Beginning duplicate detection process.")
diff --git a/kill_playlist_dupes b/kill_playlist_dupes
index eb8cca0..5824e2e 100644
--- a/kill_playlist_dupes
+++ b/kill_playlist_dupes
@@ -3,7 +3,20 @@ import sys
 
 from gmusicapi import Mobileclient
 
-
+try:
+    import credentials
+    # credentials.py is in .gitignore and can be shared with other scripts
+    username = credentials.username
+    password = credentials.password
+except ImportError:
+    username = 'username'
+    password = 'password'
+
+try:
+    # optionally hardcode id to workaround https://github.com/simon-weber/gmusicapi/issues/408
+    android_id = credentials.android_id
+except (NameError, AttributeError):
+    android_id = Mobileclient.FROM_MAC_ADDRESS
 
 def get_dupes_in_playlist(playlist):
    duplicate_Ids = []
@@ -58,7 +71,7 @@ def query_yes_no(question, default="yes"):
 
 
 api = Mobileclient()
-logged_in = api.login('username', 'password', Mobileclient.FROM_MAC_ADDRESS)
+logged_in = api.login(username, password, android_id)
 
 if logged_in:
     print("Successfully logged in. Beginning duplicate detection process.")