diff --git a/src/mpd_now_playable/mpd/listener.py b/src/mpd_now_playable/mpd/listener.py
index 01a1aaf..75852f7 100644
--- a/src/mpd_now_playable/mpd/listener.py
+++ b/src/mpd_now_playable/mpd/listener.py
@@ -49,7 +49,7 @@ def mpd_state_to_song(config: MpdConfig, mpd: MpdState) -> Song:
 		genre=un_maybe_plural(mpd.current.get("genre")),
 		track=option_fmap(int, mpd.current.get("track")),
 		disc=option_fmap(int, mpd.current.get("disc")),
-		duration=float(mpd.status["duration"]),
+		duration=option_fmap(float, mpd.status.get("duration")),
 		elapsed=float(mpd.status["elapsed"]),
 		musicbrainz=to_brainz(mpd.current),
 		art=to_artwork(mpd.art),
diff --git a/src/mpd_now_playable/mpd/types.py b/src/mpd_now_playable/mpd/types.py
index 98f6612..8d9db81 100644
--- a/src/mpd_now_playable/mpd/types.py
+++ b/src/mpd_now_playable/mpd/types.py
@@ -20,8 +20,11 @@ OneshotFlag = Literal[BooleanFlag, "oneshot"]
 class StatusResponse(TypedDict):
 	state: Literal["play", "stop", "pause"]
 
-	# The total duration and elapsed playback of the current song, measured in seconds. Fractional seconds are allowed.
-	duration: str
+	# The total duration and elapsed playback of the current song, measured in
+	# seconds. Fractional seconds are allowed. The duration field may be
+	# omitted because MPD cannot determine the duration of certain sources,
+	# such as Internet radio streams.
+	duration: NotRequired[str]
 	elapsed: str
 
 	# The volume value ranges from 0-100. It may be omitted from
diff --git a/src/mpd_now_playable/song/song.py b/src/mpd_now_playable/song/song.py
index 3b2bbe1..45c4425 100644
--- a/src/mpd_now_playable/song/song.py
+++ b/src/mpd_now_playable/song/song.py
@@ -69,8 +69,9 @@ class Song:
 	genre: list[str]
 
 	#: The song's duration as read from its tags, measured in seconds.
-	#: Fractional seconds are allowed.
-	duration: float
+	#: Fractional seconds are allowed. The duration may be unavailable for some
+	#: sources, such as internet radio streams.
+	duration: float | None
 
 	#: How far into the song MPD is, measured in seconds. Fractional seconds
 	#: are allowed. This is usually going to be less than or equal to the