diff --git a/synth/voice_allocator.h b/synth/voice_allocator.h
index 0d9dd66..f9b6984 100644
--- a/synth/voice_allocator.h
+++ b/synth/voice_allocator.h
@@ -2,6 +2,8 @@
 #include "ivoice.h"
 #include "midi_event.h"
 #include <vector>
+#include <memory>
+#include <algorithm>
 
 namespace trnr {