diff --git a/ISLE/isleapp.cpp b/ISLE/isleapp.cpp
index 3044c0a0..6901a298 100644
--- a/ISLE/isleapp.cpp
+++ b/ISLE/isleapp.cpp
@@ -1,5 +1,6 @@
 #include "isleapp.h"
 
+#include "decomp.h"
 #include "define.h"
 #include "legoanimationmanager.h"
 #include "legobuildingmanager.h"
@@ -23,9 +24,11 @@
 
 #include <dsound.h>
 
+DECOMP_SIZE_ASSERT(IsleApp, 0x8c)
+
 // Might be static functions of IsleApp
-BOOL FindExistingInstance(void);
-BOOL StartDirectSound(void);
+BOOL FindExistingInstance();
+BOOL StartDirectSound();
 
 // FUNCTION: ISLE 0x401000
 IsleApp::IsleApp()
@@ -299,7 +302,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine
 }
 
 // FUNCTION: ISLE 0x401ca0
-BOOL FindExistingInstance(void)
+BOOL FindExistingInstance()
 {
 	HWND hWnd = FindWindowA(WNDCLASS_NAME, WINDOW_TITLE);
 	if (hWnd) {
@@ -312,7 +315,7 @@ BOOL FindExistingInstance(void)
 }
 
 // FUNCTION: ISLE 0x401ce0
-BOOL StartDirectSound(void)
+BOOL StartDirectSound()
 {
 	LPDIRECTSOUND lpDS = NULL;
 	HRESULT ret = DirectSoundCreate(NULL, &lpDS, NULL);
diff --git a/ISLE/isleapp.h b/ISLE/isleapp.h
index 1e692cb1..1fb49a94 100644
--- a/ISLE/isleapp.h
+++ b/ISLE/isleapp.h
@@ -1,11 +1,11 @@
 #ifndef ISLEAPP_H
 #define ISLEAPP_H
 
-#include "mxtypes.h"
 #include "mxvideoparam.h"
 
 #include <windows.h>
 
+// SIZE 0x8c
 class IsleApp {
 public:
 	IsleApp();
@@ -46,48 +46,33 @@ class IsleApp {
 	inline void SetWindowActive(BOOL p_windowActive) { m_windowActive = p_windowActive; }
 
 private:
-	// 0
-	LPSTR m_hdPath;
-	LPSTR m_cdPath;
-	LPSTR m_deviceId;
-	LPSTR m_savePath;
-
-	// 10
-	BOOL m_fullScreen;
-	BOOL m_flipSurfaces;
-	BOOL m_backBuffersInVram;
-	BOOL m_using8bit;
-
-	// 20
-	BOOL m_using16bit;
-	int m_unk0x24;
-	BOOL m_use3dSound;
-	BOOL m_useMusic;
-
-	// 30
-	BOOL m_useJoystick;
-	int m_joystickIndex;
-	BOOL m_wideViewAngle;
-	int m_islandQuality;
-
-	// 40
-	int m_islandTexture;
-	int m_gameStarted;
-	MxLong m_frameDelta;
-
-	// 4c
-	MxVideoParam m_videoParam;
-
-	// 70
-	BOOL m_windowActive;
-	HWND m_windowHandle;
-	BOOL m_drawCursor;
-	HCURSOR m_cursorArrow;
-
-	// 80
-	HCURSOR m_cursorBusy;
-	HCURSOR m_cursorNo;
-	HCURSOR m_cursorCurrent;
+	LPSTR m_hdPath;            // 0x00
+	LPSTR m_cdPath;            // 0x04
+	LPSTR m_deviceId;          // 0x08
+	LPSTR m_savePath;          // 0x0c
+	BOOL m_fullScreen;         // 0x10
+	BOOL m_flipSurfaces;       // 0x14
+	BOOL m_backBuffersInVram;  // 0x18
+	BOOL m_using8bit;          // 0x1c
+	BOOL m_using16bit;         // 0x20
+	int m_unk0x24;             // 0x24
+	BOOL m_use3dSound;         // 0x28
+	BOOL m_useMusic;           // 0x2c
+	BOOL m_useJoystick;        // 0x30
+	int m_joystickIndex;       // 0x34
+	BOOL m_wideViewAngle;      // 0x38
+	int m_islandQuality;       // 0x3c
+	int m_islandTexture;       // 0x40
+	int m_gameStarted;         // 0x44
+	MxLong m_frameDelta;       // 0x48
+	MxVideoParam m_videoParam; // 0x4c
+	BOOL m_windowActive;       // 0x70
+	HWND m_windowHandle;       // 0x74
+	BOOL m_drawCursor;         // 0x78
+	HCURSOR m_cursorArrow;     // 0x7c
+	HCURSOR m_cursorBusy;      // 0x80
+	HCURSOR m_cursorNo;        // 0x84
+	HCURSOR m_cursorCurrent;   // 0x88
 };
 
 #endif // ISLEAPP_H