diff --git a/src/db/update/Container.cxx b/src/db/update/Container.cxx
index 8f11ae5f0..01f2edfa0 100644
--- a/src/db/update/Container.cxx
+++ b/src/db/update/Container.cxx
@@ -31,6 +31,7 @@
 #include "tag/TagHandler.hxx"
 #include "tag/TagBuilder.hxx"
 #include "Log.hxx"
+#include "util/AllocatedString.hxx"
 
 Directory *
 UpdateWalk::MakeDirectoryIfModified(Directory &parent, const char *name,
@@ -95,16 +96,16 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 		return false;
 	}
 
-	char *vtrack;
+	AllocatedString<> vtrack = nullptr;
 	unsigned int tnum = 0;
 	TagBuilder tag_builder;
 	while ((vtrack = plugin.container_scan(pathname, ++tnum)) != nullptr) {
-		Song *song = Song::NewFile(vtrack, *contdir);
+		Song *song = Song::NewFile(vtrack.c_str(), *contdir);
 
 		// shouldn't be necessary but it's there..
 		song->mtime = info.mtime;
 
-		const auto vtrack_fs = AllocatedPath::FromUTF8(vtrack);
+		const auto vtrack_fs = AllocatedPath::FromUTF8(vtrack.c_str());
 		// TODO: check vtrack_fs.IsNull()
 
 		const auto child_path_fs = AllocatedPath::Build(pathname,
@@ -122,8 +123,7 @@ UpdateWalk::UpdateContainerFile(Directory &directory,
 		modified = true;
 
 		FormatDefault(update_domain, "added %s/%s",
-			      directory.GetPath(), vtrack);
-		delete[] vtrack;
+			      directory.GetPath(), vtrack.c_str());
 	}
 
 	if (tnum == 1) {
diff --git a/src/decoder/DecoderPlugin.hxx b/src/decoder/DecoderPlugin.hxx
index 4bb57e14f..1c3042a18 100644
--- a/src/decoder/DecoderPlugin.hxx
+++ b/src/decoder/DecoderPlugin.hxx
@@ -26,6 +26,7 @@ struct ConfigBlock;
 class InputStream;
 struct TagHandler;
 class Path;
+template<typename T> class AllocatedString;
 
 /**
  * Opaque handle which the decoder plugin passes to the functions in
@@ -95,10 +96,8 @@ struct DecoderPlugin {
 	 * @return nullptr if there are no multiple files
 	 * a filename for every single track according to tnum (param 2)
 	 * do not include full pathname here, just the "virtual" file
-	 *
-	 * Free the return value with delete[].
 	 */
-	char* (*container_scan)(Path path_fs, const unsigned int tnum);
+	AllocatedString<char> (*container_scan)(Path path_fs, unsigned tnum);
 
 	/* last element in these arrays must always be a nullptr: */
 	const char *const*suffixes;
diff --git a/src/decoder/plugins/GmeDecoderPlugin.cxx b/src/decoder/plugins/GmeDecoderPlugin.cxx
index 0791f39e0..e853450e6 100644
--- a/src/decoder/plugins/GmeDecoderPlugin.cxx
+++ b/src/decoder/plugins/GmeDecoderPlugin.cxx
@@ -103,7 +103,7 @@ ParseContainerPath(Path path_fs)
 	return { path_fs.GetDirectoryName(), track - 1 };
 }
 
-static char *
+static AllocatedString<>
 gme_container_scan(Path path_fs, const unsigned int tnum)
 {
 	Music_Emu *emu;
@@ -123,7 +123,7 @@ gme_container_scan(Path path_fs, const unsigned int tnum)
 	const char *subtune_suffix = uri_get_suffix(path_fs.c_str());
 	if (tnum <= num_songs){
 		return FormatString(SUBTUNE_PREFIX "%03u.%s",
-				    tnum, subtune_suffix).Steal();
+				    tnum, subtune_suffix);
 	} else
 		return nullptr;
 }
diff --git a/src/decoder/plugins/SidplayDecoderPlugin.cxx b/src/decoder/plugins/SidplayDecoderPlugin.cxx
index 50c6ec4c6..3226d3794 100644
--- a/src/decoder/plugins/SidplayDecoderPlugin.cxx
+++ b/src/decoder/plugins/SidplayDecoderPlugin.cxx
@@ -336,7 +336,7 @@ sidplay_scan_file(Path path_fs,
 	return true;
 }
 
-static char *
+static AllocatedString<>
 sidplay_container_scan(Path path_fs, const unsigned int tnum)
 {
 	SidTune tune(path_fs.c_str(), nullptr, true);
@@ -353,7 +353,7 @@ sidplay_container_scan(Path path_fs, const unsigned int tnum)
 	/* Construct container/tune path names, eg.
 		Delta.sid/tune_001.sid */
 	if(tnum<=info.songs) {
-		return FormatString(SUBTUNE_PREFIX "%03u.sid", tnum).Steal();
+		return FormatString(SUBTUNE_PREFIX "%03u.sid", tnum);
 	} else
 		return nullptr;
 }