diff --git a/LEGO1/mxdsfile.cpp b/LEGO1/mxdsfile.cpp
index 77d1ed04..cf37e187 100644
--- a/LEGO1/mxdsfile.cpp
+++ b/LEGO1/mxdsfile.cpp
@@ -1,10 +1,14 @@
 #include "mxdsfile.h"
 
-#include "stdio.h"
+#include <stdio.h>
 
 #define SI_MAJOR_VERSION 2
 #define SI_MINOR_VERSION 2
 
+#define FCC_OMNI 0x494e4d4f
+#define FCC_MxHd 0x6448784d
+#define FCC_MxOf 0x664f784d
+
 // OFFSET: LEGO1 0x100cc4b0
 MxDSFile::MxDSFile(const char *filename, unsigned long skipReadingChunks)
 {
@@ -24,7 +28,7 @@ long MxDSFile::Open(unsigned long uStyle)
   // No idea what's stopping this one matching, but I'm pretty
   // confident it has the correct behavior.
   memset(&m_io, 0, sizeof(MXIOINFO));
-  if (m_io.Open(m_filename.Data(), uStyle) != 0) {
+  if (m_io.Open(m_filename.GetData(), uStyle) != 0) {
     return -1;
   }
 
@@ -62,11 +66,11 @@ long MxDSFile::ReadChunks()
   _MMCKINFO childChunk;
   char tempBuffer[80];
   
-  topChunk.fccType = 0x494e4d4f;
+  topChunk.fccType = FCC_OMNI;
   if (m_io.Descend(&topChunk, NULL, MMIO_FINDRIFF) != 0) {
     return -1;
   }
-  childChunk.ckid = 0x6448784d;
+  childChunk.ckid = FCC_MxHd;
   if (m_io.Descend(&childChunk, &topChunk, 0) != 0) {
     return -1;
   }
@@ -74,7 +78,7 @@ long MxDSFile::ReadChunks()
   m_io.Read((char*)&m_header, 0xc);
   if ((m_header.majorVersion == SI_MAJOR_VERSION) && (m_header.minorVersion == SI_MINOR_VERSION))
   {
-    childChunk.ckid = 0x664f784d;
+    childChunk.ckid = FCC_MxOf;
     if (m_io.Descend(&childChunk, &topChunk, 0) != 0) {
       return -1;
     }
@@ -87,7 +91,7 @@ long MxDSFile::ReadChunks()
   else
   {
     sprintf(tempBuffer, "Wrong SI file version. %d.%d expected.", SI_MAJOR_VERSION, SI_MINOR_VERSION);
-    MessageBoxA(NULL, tempBuffer, NULL, 0x10);
+    MessageBoxA(NULL, tempBuffer, NULL, MB_ICONERROR);
     return -1;
   }
 }
diff --git a/LEGO1/mxdsfile.h b/LEGO1/mxdsfile.h
index 86702519..e1e170d4 100644
--- a/LEGO1/mxdsfile.h
+++ b/LEGO1/mxdsfile.h
@@ -9,13 +9,13 @@ class MxDSFile : public MxDSSource
 {
 public:
   __declspec(dllexport) MxDSFile(const char *filename, unsigned long skipReadingChunks);
-  __declspec(dllexport) ~MxDSFile();
-  __declspec(dllexport) long Open(unsigned long);
-  __declspec(dllexport) long Close();
-  __declspec(dllexport) long Read(unsigned char *,unsigned long);
-  __declspec(dllexport) long Seek(long,int);
-  __declspec(dllexport) unsigned long GetBufferSize();
-  __declspec(dllexport) unsigned long GetStreamBuffersNum();
+  __declspec(dllexport) virtual ~MxDSFile();
+  __declspec(dllexport) virtual long Open(unsigned long);
+  __declspec(dllexport) virtual long Close();
+  __declspec(dllexport) virtual long Read(unsigned char *,unsigned long);
+  __declspec(dllexport) virtual long Seek(long,int);
+  __declspec(dllexport) virtual unsigned long GetBufferSize();
+  __declspec(dllexport) virtual unsigned long GetStreamBuffersNum();
 
 private:
   long ReadChunks();
diff --git a/LEGO1/mxioinfo.h b/LEGO1/mxioinfo.h
index ce8c4eb5..27aa482d 100644
--- a/LEGO1/mxioinfo.h
+++ b/LEGO1/mxioinfo.h
@@ -1,7 +1,7 @@
 #ifndef MXIOINFO_H
 #define MXIOINFO_H
 
-#include "windows.h"
+#include "legoinc.h"
 #include "mmsystem.h"
 class MXIOINFO
 {
diff --git a/LEGO1/mxstring.h b/LEGO1/mxstring.h
index 12194447..a9a25ba1 100644
--- a/LEGO1/mxstring.h
+++ b/LEGO1/mxstring.h
@@ -16,7 +16,7 @@ class MxString : public MxCore
   void ToLowerCase();
   const MxString &operator=(MxString *);
 
-  inline const char *Data() const { return m_data; }
+  inline const char *GetData() const { return m_data; }
 
 private:
   char *m_data;