diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4d4976fa..0e61a7f3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -123,6 +123,7 @@ add_library(lego1 SHARED
   LEGO1/mxloopingflcpresenter.cpp
   LEGO1/mxloopingsmkpresenter.cpp
   LEGO1/mxmediapresenter.cpp
+  LEGO1/mxmidipresenter.cpp
   LEGO1/mxmusicpresenter.cpp
   LEGO1/mxnotificationmanager.cpp
   LEGO1/mxomni.cpp
diff --git a/LEGO1/mxmidipresenter.cpp b/LEGO1/mxmidipresenter.cpp
new file mode 100644
index 00000000..94fa0a42
--- /dev/null
+++ b/LEGO1/mxmidipresenter.cpp
@@ -0,0 +1,16 @@
+#include "mxmidipresenter.h"
+
+#include "decomp.h"
+
+DECOMP_STATIC_ASSERT(sizeof(MxMIDIPresenter) == 88);
+
+// OFFSET: LEGO1 0x100c25e0
+MxMIDIPresenter::MxMIDIPresenter() {
+  Init();
+}
+
+// OFFSET: LEGO1 0x100c2820
+void MxMIDIPresenter::Init()
+{
+  m_unk54 = 0;
+}
diff --git a/LEGO1/mxmidipresenter.h b/LEGO1/mxmidipresenter.h
index 8a46d12a..1cd65c4a 100644
--- a/LEGO1/mxmidipresenter.h
+++ b/LEGO1/mxmidipresenter.h
@@ -6,6 +6,11 @@
 // VTABLE 0x100dca20
 class MxMIDIPresenter : public MxMusicPresenter
 {
+public:
+  MxMIDIPresenter();
+private:
+  void Init();
+  undefined4 m_unk54;
 };
 
 #endif // MXMIDIPRESENTER_H