diff --git a/sim_defs.h b/sim_defs.h
index 0eaca5e9..bc3246d6 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -181,16 +181,28 @@ extern "C" {
 
 /* Length specific integer declarations */
 
+/* Handle the special/unusual cases first with everything else leveraging stdints.h */
 #if defined (VMS)
 #include <ints.h>
-#else
-typedef signed char     int8;
-typedef signed short    int16;
-typedef signed int      int32;
-typedef unsigned char   uint8;
-typedef unsigned short  uint16;
-typedef unsigned int    uint32;
-#endif
+#elif defined(_MSC_VER) && (_MSC_VER < 1600)
+typedef __int8           int8;
+typedef __int16          int16;
+typedef __int32          int32;
+typedef unsigned __int8  uint8;
+typedef unsigned __int16 uint16;
+typedef unsigned __int32 uint32;
+#else                                                   
+/* All modern/standard compiler environments */
+/* any other environment needa a special case above */
+#include <stdint.h>
+typedef int8_t          int8;
+typedef int16_t         int16;
+typedef int32_t         int32;
+typedef uint8_t         uint8;
+typedef uint16_t        uint16;
+typedef uint32_t        uint32;
+#endif                                                  /* end standard integers */
+
 typedef int             t_stat;                         /* status */
 typedef int             t_bool;                         /* boolean */