diff --git a/src/System.h b/src/System.h
index 6a550b1d..bbae9749 100644
--- a/src/System.h
+++ b/src/System.h
@@ -20,32 +20,28 @@
 #ifndef VBA_SYSTEM_H
 #define VBA_SYSTEM_H
 
+#include <stdint.h>
+
 #include "unzip.h"
 
 #ifndef NULL
 #define NULL 0
 #endif
 
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef int8_t s8;
+typedef int16_t s16;
+typedef int32_t s32;
+typedef int64_t s64;
+
 typedef unsigned char u8;
 typedef unsigned short u16;
 typedef unsigned int u32;
 
-#ifdef _MSC_VER
-typedef unsigned __int64 u64;
-#else
-typedef unsigned long long u64;
-#endif
-
-typedef signed char s8;
-typedef signed short s16;
-typedef signed int s32;
-
-#ifdef _MSC_VER
-typedef signed __int64 s64;
-#else
-typedef signed long long s64;
-#endif
-
 struct EmulatedSystem {
   // main emulation function
   void (*emuMain)(int);