diff --git a/Storage/Disk/PCMPatchedTrack.cpp b/Storage/Disk/PCMPatchedTrack.cpp
index 0900a3d8a..0d1502f3d 100644
--- a/Storage/Disk/PCMPatchedTrack.cpp
+++ b/Storage/Disk/PCMPatchedTrack.cpp
@@ -22,11 +22,11 @@ PCMPatchedTrack::PCMPatchedTrack(std::shared_ptr<Track> underlying_track) :
 
 void PCMPatchedTrack::add_segment(const Time &start_time, const PCMSegment &segment)
 {
-	event_sources_.emplace_back(segment);
+	std::shared_ptr<PCMSegmentEventSource> event_source(new PCMSegmentEventSource(segment));
 
 	Time zero(0);
-	Time end_time = start_time + event_sources_.back().get_length();
-	Period insertion_period(start_time, end_time, zero, &event_sources_.back());
+	Time end_time = start_time + event_source->get_length();
+	Period insertion_period(start_time, end_time, zero, event_source);
 
 	// the new segment may wrap around, so divide it up into track-length parts if required
 	Time one = Time(1);
diff --git a/Storage/Disk/PCMPatchedTrack.hpp b/Storage/Disk/PCMPatchedTrack.hpp
index 31523347e..d18b88e0b 100644
--- a/Storage/Disk/PCMPatchedTrack.hpp
+++ b/Storage/Disk/PCMPatchedTrack.hpp
@@ -38,14 +38,13 @@ class PCMPatchedTrack: public Track {
 
 	private:
 		std::shared_ptr<Track> underlying_track_;
-		std::vector<PCMSegmentEventSource> event_sources_;
 
 		struct Period {
 			Time start_time, end_time;
 			Time segment_start_time;
-			PCMSegmentEventSource *event_source;	// nullptr => use the underlying track
+			std::shared_ptr<PCMSegmentEventSource> event_source; // nullptr => use the underlying track
 
-			Period(const Time &start_time, const Time &end_time, const Time &segment_start_time, PCMSegmentEventSource *event_source) :
+			Period(const Time &start_time, const Time &end_time, const Time &segment_start_time, std::shared_ptr<PCMSegmentEventSource> event_source) :
 				start_time(start_time), end_time(end_time), segment_start_time(segment_start_time), event_source(event_source) {}
 		};
 		std::vector<Period> periods_;