diff --git a/vms/config.h b/vms/config.h
new file mode 100644
index 0000000000..70a584f33d
--- /dev/null
+++ b/vms/config.h
@@ -0,0 +1,120 @@
+#define HAVE_ACOSH 1
+/* #define HAVE_ALLOCA_H 1 */
+/* #define HAVE_CHROOT 1 */
+#define HAVE_COSH 1
+/* #define HAVE_CRYPT 1 */
+#define HAVE_DAYLIGHT 1
+#define HAVE_DECL_SYS_NERR 1
+#define HAVE_DIRENT_H 1
+#define HAVE_DLOPEN 1
+#define HAVE_DUP2 1
+/* #define HAVE_FCHMOD 1 */
+#define HAVE_FCNTL 1
+#define HAVE_FCNTL_H 1
+#define HAVE_FINITE 1
+#define HAVE_FLOCK 1
+#define HAVE_FMOD 1
+#define HAVE_FREXP 1
+/* #define HAVE_FSEEKO 1 */
+#define HAVE_FSYNC 1
+/* #define HAVE_FTELLO 1 */
+#define HAVE_GETCWD 1
+/* #define HAVE_GETPGID 1 xxxx */
+#define HAVE_GETPGRP 1
+/* #define HAVE_GETPRIORITY 1 */
+/* #define HAVE_GETRLIMIT 1 */
+#define HAVE_HYPOT 1
+#define HAVE_ISASCII 1
+/* #define HAVE_ISINF 1 */
+#define HAVE_ISNAN 1
+/* #define HAVE_LCHMOD 1 */
+/* #define HAVE_LCHOWN 1 */
+#define HAVE_LONG_LONG 1 
+/* #define HAVE_LSTAT 1 */
+#define HAVE_MEMCMP 1
+#define HAVE_MEMMOVE 1
+#define HAVE_MKDIR 1
+#define HAVE_MKTIME 1
+#define HAVE_MODF 1
+#define HAVE_OFF_T 1
+#define HAVE_PAUSE 1
+/* #define HAVE_PROTOTYPES 1 */
+/* #define HAVE_PWD_H 1 */
+/* #define HAVE_READLINK 1 */
+#define HAVE_SEEKDIR 1
+/* #define HAVE_SETITIMER 1 */
+/* #define HAVE_SETPGID 1 xxxx */
+/* #define HAVE_SETRESGID 1 */
+/* #define HAVE_SETRESUID 1 */
+/* #define HAVE_SETSID 1 xxxx */
+#define HAVE_SIGPROCMASK 1
+#define HAVE_SINH 1
+#define HAVE_STDARG_PROTOTYPES 1
+#define HAVE_STDLIB_H 1
+#define HAVE_STRCASECMP 1
+#define HAVE_STRCHR 1
+#define HAVE_STRERROR 1
+#define HAVE_STRFTIME 1
+#define HAVE_STRING_H 1
+#define HAVE_STRNCASECMP 1
+#define HAVE_STRSTR 1
+#define HAVE_STRTOD 1
+#define HAVE_STRTOL 1
+#define HAVE_STRTOUL 1
+#define HAVE_STRUCT_TM_TM_GMTOFF 1
+/* #define HAVE_ST_BLKSIZE 1 */
+/* #define HAVE_ST_BLOCKS 1 */
+#define HAVE_ST_RDEV 1
+/* #define HAVE_SYMLINK 1 */
+/* #define HAVE_SYSCALL 1 */
+#define HAVE_SYS_FILE_H 1
+/* #define HAVE_SYS_MKDEV_H 1 */
+/* #define HAVE_SYS_PARAM_H 1 */
+#define HAVE_SYS_RESOURCE_H 1
+/* #define HAVE_SYS_SELECT_H 1 */
+#define HAVE_SYS_TIMES_H 1
+#define HAVE_SYS_TIME_H 1
+#define HAVE_SYS_WAIT_H 1
+#define HAVE_TANH 1
+#define HAVE_TELLDIR 1
+/* #define HAVE_TIMEGM 1 */
+#define HAVE_TIMES 1
+#define HAVE_TM_ZONE 1
+#define HAVE_TRUNCATE 1
+#define HAVE_TZNAME 1
+#define HAVE_UNISTD_H 1
+#define HAVE_UTIMES 1
+#define HAVE_UTIME_H 1
+/* #define HAVE_VSNPRINTF 1 */
+#define HAVE_WAIT4 1
+#define HAVE_WAITPID 1
+ #define HAVE__SETJMP 1
+
+#define GETGROUPS_T gid_t
+#define RETSIGTYPE void
+
+#define RSHIFT(x,y) ((x)>>y)
+#define DEFAULT_KCODE KCODE_EUC
+#define DLEXT ".EXE"
+#define DLEXT2 ""
+#define RUBY_LIB "/RUBY_LIB"
+#define RUBY_SITE_LIB "/RUBY_SYSLIB"
+#define RUBY_SITE_LIB2 "/SYS$SHARE"
+#define RUBY_ARCHLIB ""
+#define RUBY_SITE_ARCHLIB ""
+#define SIZEOF_INT 4
+#define SIZEOF_SHORT 2
+#define SIZEOF_LONG 4
+#define SIZEOF_VOIDP 4
+#define SIZEOF_FLOAT 4
+#define SIZEOF_DOUBLE 8
+
+#if defined(__vax)
+#define RUBY_PLATFORM "vax-vms"
+#elif defined(__alpha)
+#define RUBY_PLATFORM "alpha-vms"
+#elif defined(__ia-64)
+#define RUBY_PLATFORM "ia64-vms"
+#else
+#define RUBY_PLATFORM "vms"
+#endif
diff --git a/vms/config.h_in b/vms/config.h_in
deleted file mode 100644
index 2fd3e26629..0000000000
--- a/vms/config.h_in
+++ /dev/null
@@ -1,61 +0,0 @@
-/* config.h for OpenVMS Alpha */
-
-/* #define HAVE_PROTOTYPES 1 */
-#define HAVE_STDARG_PROTOTYPES 1
-/* #define HAVE_ATTR_NORETURN 1 */
-/* #define inline __inline */
-#define HAVE_DIRENT_H 1
-#define HAVE_UNISTD_H 1
-#define HAVE_STDLIB_H 1
-#define HAVE_LIMITS_H 1
-
-#define HAVE_SYS_FILE_H 1
-#define HAVE_FCNTL_H 1
-/* #define HAVE_PWD_H 1 */
-#define HAVE_SYS_TIME_H 1
-#define HAVE_SYS_TIMES_H 1
-/* #define HAVE_SYS_PARAM_H 1 */
-#define HAVE_SYS_WAIT_H 1
-#define HAVE_STRING_H 1
-#define HAVE_UTIME_H 1
-#define HAVE_MEMORY_H 1
-/* #define HAVE_ST_BLKSIZE 1  */
-#define HAVE_ST_RDEV 1
-/* #define GETGROUPS_T gid_t */
-#define GETGROUPS_T int
-#define RETSIGTYPE void
-/* #define HAVE_ALLOCA 1 */
-/* #define vfork fork */
-#define HAVE_FMOD 1
-#define HAVE_RANDOM 1
-#define HAVE_WAITPID 1
-#define HAVE_GETCWD 1
-#define HAVE_TRUNCATE 1
-/* #define HAVE_CHSIZE 1 */
-#define HAVE_TIMES 1
-/* #define HAVE_UTIMES 1 */
-#define HAVE_FCNTL 1
-/* #define HAVE_SETITIMER 1 */
-/* #define HAVE_GETGROUPS 1 */
-#define HAVE_SIGPROCMASK 1
-#define HAVE_GETLOGIN 1
-#define HAVE_TELLDIR 1
-#define HAVE_SEEKDIR 1
-
-#define RSHIFT(x,y) ((x)>>y)
-#define DEFAULT_KCODE KCODE_NONE
-#define DLEXT ".EXE"
-/* #define DLEXT2 "" */
-#define RUBY_LIB "/RUBY_LIB"
-#define RUBY_SITE_LIB "/RUBY_SYSLIB"
-#define RUBY_SITE_LIB2 "/SYS$SHARE"
-#define RUBY_PLATFORM "alpha-vms"
-#define RUBY_ARCHLIB ""
-#define RUBY_SITE_ARCHLIB ""
-
-#define SIZEOF_INT   4
-#define SIZEOF_SHORT 2
-#define SIZEOF_LONG  4
-#define SIZEOF_VOIDP 4
-#define SIZEOF_FLOAT 4
-#define SIZEOF_DOUBLE 8