diff --git a/audible.py b/audible.py
index a858ccf..36048d9 100644
--- a/audible.py
+++ b/audible.py
@@ -70,7 +70,7 @@ def __init__(self):
         self.add_media_field('series_name', series_name)
         series_position = mediafile.MediaField(
             mediafile.MP3StorageStyle(u'MVIN'),
-            mediafile.MP3DescStorageStyle(u'SERIESPOSITION'),
+            mediafile.MP3DescStorageStyle(u'SERIES-PART'),
             # Using the "mvi" tag for M4b wouldn't work when the value can't be converted to an integer
             # For instance, an m4b containing multiple books has series position "1-3"
             # Trying to do so would cause an exception, hence why this is commented out here
diff --git a/readme.md b/readme.md
index ef264de..522c979 100644
--- a/readme.md
+++ b/readme.md
@@ -218,7 +218,7 @@ The plugin writes the following tags:
 | `MVNM` (MOVEMENTNAME)                    | Series                                                                                                                              |
 | `MVIN` / `MVI` for m4b files (MOVEMENT)  | Series Book #                                                                                                                       |
 | `TXXX_SERIES` (SERIES)                   | Series                                                                                                                              |
-| `TXXX_SERIESPART`                        | Series position                                                                                                                     |
+| `TXXX_SERIES-PART`                       | Series position                                                                                                                     |
 
 ## Known Limitations