diff --git a/lb_content_resolver/formats/flac.py b/lb_content_resolver/formats/flac.py
index bc384c0..ae69778 100755
--- a/lb_content_resolver/formats/flac.py
+++ b/lb_content_resolver/formats/flac.py
@@ -19,7 +19,7 @@ def read(file):
     mdata["release_name"] = get_tag_value(tags, "album")
     mdata["recording_name"] = get_tag_value(tags, "title")
     mdata["track_num"] = extract_track_number(get_tag_value(tags, "tracknumber"))
-    mdata["disc_num"] = int(get_tag_value(tags, "discnumber"))
+    mdata["disc_num"] = int(get_tag_value(tags, "discnumber") or 1)
     mdata["artist_mbid"] = get_tag_value(tags, "musicbrainz_artistid")
     mdata["recording_mbid"] = get_tag_value(tags, "musicbrainz_trackid")
     mdata["release_mbid"] = get_tag_value(tags, "musicbrainz_albumid")
diff --git a/lb_content_resolver/formats/mp3.py b/lb_content_resolver/formats/mp3.py
index a4a442b..98ae4e9 100755
--- a/lb_content_resolver/formats/mp3.py
+++ b/lb_content_resolver/formats/mp3.py
@@ -45,7 +45,7 @@ def read(file):
     if "TPOS" in tags:
         mdata["disc_num"] = extract_track_number(str(tags["TPOS"]))
     else:
-        mdata["disc_num"] = 0
+        mdata["disc_num"] = 1
 
     if "TXXX:MusicBrainz Artist Id" in tags:
         id = str(tags["TXXX:MusicBrainz Artist Id"])
diff --git a/lb_content_resolver/formats/ogg_opus.py b/lb_content_resolver/formats/ogg_opus.py
index 6de53c7..13ecf52 100755
--- a/lb_content_resolver/formats/ogg_opus.py
+++ b/lb_content_resolver/formats/ogg_opus.py
@@ -19,7 +19,7 @@ def read(file):
     mdata["release_name"] = get_tag_value(tags, "album")
     mdata["recording_name"] = get_tag_value(tags, "title")
     mdata["track_num"] = extract_track_number(get_tag_value(tags, "tracknumber"))
-    mdata["disc_num"] = int(get_tag_value(tags, "discnumber"))
+    mdata["disc_num"] = int(get_tag_value(tags, "discnumber") or 1)
     mdata["artist_mbid"] = get_tag_value(tags, "musicbrainz_artistid", "")
     mdata["recording_mbid"] = get_tag_value(tags, "musicbrainz_trackid", "")
     mdata["release_mbid"] = get_tag_value(tags, "musicbrainz_albumid", "")
diff --git a/lb_content_resolver/formats/ogg_vorbis.py b/lb_content_resolver/formats/ogg_vorbis.py
index fcf1b9b..9f76463 100755
--- a/lb_content_resolver/formats/ogg_vorbis.py
+++ b/lb_content_resolver/formats/ogg_vorbis.py
@@ -19,7 +19,7 @@ def read(file):
     mdata["release_name"] = get_tag_value(tags, "album")
     mdata["recording_name"] = get_tag_value(tags, "title")
     mdata["track_num"] = extract_track_number(get_tag_value(tags, "tracknumber"))
-    mdata["disc_num"] = int(get_tag_value(tags, "discnumber"))
+    mdata["disc_num"] = int(get_tag_value(tags, "discnumber") or 1)
     mdata["artist_mbid"] = get_tag_value(tags, "musicbrainz_artistid", "")
     mdata["recording_mbid"] = get_tag_value(tags, "musicbrainz_trackid", "")
     mdata["release_mbid"] = get_tag_value(tags, "musicbrainz_albumid", "")
diff --git a/lb_content_resolver/formats/wma.py b/lb_content_resolver/formats/wma.py
index 040abd8..bde38e9 100755
--- a/lb_content_resolver/formats/wma.py
+++ b/lb_content_resolver/formats/wma.py
@@ -19,7 +19,7 @@ def read(file):
     mdata["release_name"] = str(get_tag_value(tags, "WM/AlbumTitle"))
     mdata["recording_name"] = str(get_tag_value(tags, "Title"))
     mdata["track_num"] = extract_track_number(str(get_tag_value(tags, "WM/TrackNumber")))
-    mdata["disc_num"] = int(get_tag_value(tags, "WM/SetSubTitle"))
+    mdata["disc_num"] = int(get_tag_value(tags, "WM/SetSubTitle") or 1)
     mdata["artist_mbid"] = str(get_tag_value(tags, "MusicBrainz/Artist Id"))
     mdata["recording_mbid"] = str(get_tag_value(tags, "MusicBrainz/Release Track Id"))
     mdata["release_mbid"] = str(get_tag_value(tags, "MusicBrainz/Album Id"))