diff --git a/beetsplug/smartplaylist.py b/beetsplug/smartplaylist.py
index a3b24b5693..71f7160c4f 100644
--- a/beetsplug/smartplaylist.py
+++ b/beetsplug/smartplaylist.py
@@ -14,8 +14,8 @@
 
 """Generates smart playlists based on beets queries."""
 
-import json
 import os
+from urllib.parse import quote
 from urllib.request import pathname2url
 
 from beets import ui
@@ -327,7 +327,8 @@ def update_playlists(self, lib, pretend=False):
                         if extm3u:
                             attr = [(k, entry.item[k]) for k in keys]
                             al = [
-                                f" {a[0]}={json.dumps(str(a[1]))}" for a in attr
+                                f" {a[0]}=\"{quote(str(a[1]), safe='/:')}\""
+                                for a in attr
                             ]
                             attrs = "".join(al)
                             comment = "#EXTINF:{}{},{} - {}\n".format(
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 9fb3b9e3ff..4487d015f1 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -38,6 +38,8 @@ Other changes:
   wrong (outdated) commit. Now the tag is created in the same workflow step
   right after committing the version update.
   :bug:`5539`
+* :doc:`/plugins/smartplaylist`: URL-encode additional item `fields` within generated
+  EXTM3U playlists instead of JSON-encoding them.
 
 2.2.0 (December 02, 2024)
 -------------------------
diff --git a/test/plugins/test_smartplaylist.py b/test/plugins/test_smartplaylist.py
index a50f3e6227..ade745c17d 100644
--- a/test/plugins/test_smartplaylist.py
+++ b/test/plugins/test_smartplaylist.py
@@ -283,7 +283,7 @@ def test_playlist_update_output_extm3u_fields(self):
         assert (
             content
             == b"#EXTM3U\n"
-            + b'#EXTINF:300 id="456" genre="Fake Genre",Fake Artist - fake Title\n'
+            + b'#EXTINF:300 id="456" genre="Fake%20Genre",Fake Artist - fake Title\n'
             + b"/tagada.mp3\n"
         )