diff --git a/runtime/doc/todo.txt b/runtime/doc/todo.txt
index 4d7674b..02a2f42 100644
--- a/runtime/doc/todo.txt
+++ b/runtime/doc/todo.txt
@@ -1097,8 +1097,6 @@
 - Do profiling on sha256 code to find obvious bottlenecks.
 - Do profiling on crypt code to find obvious bottlenecks.
 Patches to include:
-- Use off_t instead of long for bytes in a buffer. (James Vega, 2010 May 22,
-  update next day)
 - Include conceal patch?
   http://vince.negri.googlepages.com/
   http://vim.wikia.com/wiki/Patch_to_conceal_parts_of_lines
diff --git a/src/auto/configure b/src/auto/configure
index 77dea5d..b87825f 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -2012,6 +2012,184 @@
   eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;}
 
 } # ac_fn_c_find_uintX_t
+
+# ac_fn_c_compute_int LINENO EXPR VAR INCLUDES
+# --------------------------------------------
+# Tries to find the compile-time value of EXPR in a program that includes
+# INCLUDES, setting VAR accordingly. Returns whether the value could be
+# computed
+ac_fn_c_compute_int ()
+{
+  as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+  if test "$cross_compiling" = yes; then
+    # Depending upon the size, compute the lo and hi bounds.
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+static int test_array [1 - 2 * !(($2) >= 0)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_lo=0 ac_mid=0
+  while :; do
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+static int test_array [1 - 2 * !(($2) <= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_hi=$ac_mid; break
+else
+  as_fn_arith $ac_mid + 1 && ac_lo=$as_val
+			if test $ac_lo -le $ac_mid; then
+			  ac_lo= ac_hi=
+			  break
+			fi
+			as_fn_arith 2 '*' $ac_mid + 1 && ac_mid=$as_val
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  done
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+static int test_array [1 - 2 * !(($2) < 0)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_hi=-1 ac_mid=-1
+  while :; do
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+static int test_array [1 - 2 * !(($2) >= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_lo=$ac_mid; break
+else
+  as_fn_arith '(' $ac_mid ')' - 1 && ac_hi=$as_val
+			if test $ac_mid -le $ac_hi; then
+			  ac_lo= ac_hi=
+			  break
+			fi
+			as_fn_arith 2 '*' $ac_mid && ac_mid=$as_val
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  done
+else
+  ac_lo= ac_hi=
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+# Binary search between lo and hi bounds.
+while test "x$ac_lo" != "x$ac_hi"; do
+  as_fn_arith '(' $ac_hi - $ac_lo ')' / 2 + $ac_lo && ac_mid=$as_val
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+int
+main ()
+{
+static int test_array [1 - 2 * !(($2) <= $ac_mid)];
+test_array [0] = 0
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_hi=$ac_mid
+else
+  as_fn_arith '(' $ac_mid ')' + 1 && ac_lo=$as_val
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+done
+case $ac_lo in #((
+?*) eval "$3=\$ac_lo"; ac_retval=0 ;;
+'') ac_retval=1 ;;
+esac
+  else
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+$4
+static long int longval () { return $2; }
+static unsigned long int ulongval () { return $2; }
+#include <stdio.h>
+#include <stdlib.h>
+int
+main ()
+{
+
+  FILE *f = fopen ("conftest.val", "w");
+  if (! f)
+    return 1;
+  if (($2) < 0)
+    {
+      long int i = longval ();
+      if (i != ($2))
+	return 1;
+      fprintf (f, "%ld", i);
+    }
+  else
+    {
+      unsigned long int i = ulongval ();
+      if (i != ($2))
+	return 1;
+      fprintf (f, "%lu", i);
+    }
+  /* Do not output a trailing newline, as this causes \r\n confusion
+     on some platforms.  */
+  return ferror (f) || fclose (f) != 0;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_run "$LINENO"; then :
+  echo >>conftest.val; read $3 <conftest.val; ac_retval=0
+else
+  ac_retval=1
+fi
+rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
+  conftest.$ac_objext conftest.beam conftest.$ac_ext
+rm -f conftest.val
+
+  fi
+  eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;}
+  as_fn_set_status $ac_retval
+
+} # ac_fn_c_compute_int
 cat >auto/config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
@@ -11195,92 +11373,143 @@
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
-
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking size of int" >&5
 $as_echo_n "checking size of int... " >&6; }
 if test "${ac_cv_sizeof_int+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
-  if test "$cross_compiling" = yes; then :
-  as_fn_error "failed to compile test program" "$LINENO" 5
+  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (int))" "ac_cv_sizeof_int"        "$ac_includes_default"; then :
+
 else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#include <stdio.h>
-#if STDC_HEADERS
-# include <stdlib.h>
-# include <stddef.h>
-#endif
-main()
-{
-  FILE *f=fopen("conftestval", "w");
-  if (!f) exit(1);
-  fprintf(f, "%d\n", (int)sizeof(int));
-  exit(0);
-}
-_ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
-  ac_cv_sizeof_int=`cat conftestval`
-else
-  as_fn_error "failed to determine sizeof(int)" "$LINENO" 5
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  if test "$ac_cv_type_int" = yes; then
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (int)
+See \`config.log' for more details." "$LINENO" 5; }; }
+   else
+     ac_cv_sizeof_int=0
+   fi
 fi
 
 fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_int" >&5
 $as_echo "$ac_cv_sizeof_int" >&6; }
+
+
+
 cat >>confdefs.h <<_ACEOF
 #define SIZEOF_INT $ac_cv_sizeof_int
 _ACEOF
 
 
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of long" >&5
+$as_echo_n "checking size of long... " >&6; }
+if test "${ac_cv_sizeof_long+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (long))" "ac_cv_sizeof_long"        "$ac_includes_default"; then :
+
+else
+  if test "$ac_cv_type_long" = yes; then
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (long)
+See \`config.log' for more details." "$LINENO" 5; }; }
+   else
+     ac_cv_sizeof_long=0
+   fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_long" >&5
+$as_echo "$ac_cv_sizeof_long" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_LONG $ac_cv_sizeof_long
+_ACEOF
+
+
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking size of time_t" >&5
 $as_echo_n "checking size of time_t... " >&6; }
 if test "${ac_cv_sizeof_time_t+set}" = set; then :
   $as_echo_n "(cached) " >&6
 else
-  if test "$cross_compiling" = yes; then :
-  as_fn_error "failed to compile test program" "$LINENO" 5
+  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (time_t))" "ac_cv_sizeof_time_t"        "$ac_includes_default"; then :
+
 else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#include <stdio.h>
-#if STDC_HEADERS
-# include <stdlib.h>
-# include <stddef.h>
-#endif
-#include <time.h>
-main()
-{
-  FILE *f=fopen("conftestval", "w");
-  if (!f) exit(1);
-  fprintf(f, "%d\n", (int)sizeof(time_t));
-  exit(0);
-}
-_ACEOF
-if ac_fn_c_try_run "$LINENO"; then :
-  ac_cv_sizeof_time_t=`cat conftestval`
-else
-  as_fn_error "failed to determine sizeof(time_t)" "$LINENO" 5
-fi
-rm -f core *.core core.conftest.* gmon.out bb.out conftest$ac_exeext \
-  conftest.$ac_objext conftest.beam conftest.$ac_ext
+  if test "$ac_cv_type_time_t" = yes; then
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (time_t)
+See \`config.log' for more details." "$LINENO" 5; }; }
+   else
+     ac_cv_sizeof_time_t=0
+   fi
 fi
 
 fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_time_t" >&5
 $as_echo "$ac_cv_sizeof_time_t" >&6; }
+
+
+
 cat >>confdefs.h <<_ACEOF
 #define SIZEOF_TIME_T $ac_cv_sizeof_time_t
 _ACEOF
 
 
+# The cast to long int works around a bug in the HP C Compiler
+# version HP92453-01 B.11.11.23709.GP, which incorrectly rejects
+# declarations like `int a3[[(sizeof (unsigned char)) >= 0]];'.
+# This bug is HP SR number 8606223364.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking size of off_t" >&5
+$as_echo_n "checking size of off_t... " >&6; }
+if test "${ac_cv_sizeof_off_t+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  if ac_fn_c_compute_int "$LINENO" "(long int) (sizeof (off_t))" "ac_cv_sizeof_off_t"        "$ac_includes_default"; then :
+
+else
+  if test "$ac_cv_type_off_t" = yes; then
+     { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+{ as_fn_set_status 77
+as_fn_error "cannot compute sizeof (off_t)
+See \`config.log' for more details." "$LINENO" 5; }; }
+   else
+     ac_cv_sizeof_off_t=0
+   fi
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_sizeof_off_t" >&5
+$as_echo "$ac_cv_sizeof_off_t" >&6; }
+
+
+
+cat >>confdefs.h <<_ACEOF
+#define SIZEOF_OFF_T $ac_cv_sizeof_off_t
+_ACEOF
+
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking uint32_t is 32 bits" >&5
 $as_echo_n "checking uint32_t is 32 bits... " >&6; }
 if test "$cross_compiling" = yes; then :
diff --git a/src/config.h.in b/src/config.h.in
index 1099531..f6c4561 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -39,6 +39,12 @@
 /* Defined to the size of an int */
 #undef SIZEOF_INT
 
+/* Defined to the size of a long */
+#undef SIZEOF_LONG
+
+/* Defined to the size of off_t */
+#undef SIZEOF_OFF_T
+
 /* Defined to the size of time_t */
 #undef SIZEOF_TIME_T
 
@@ -251,12 +257,13 @@
 #undef HAVE_SYS_SYSINFO_H
 #undef HAVE_SYS_SYSTEMINFO_H
 #undef HAVE_SYS_TIME_H
+#undef HAVE_SYS_TYPES_H
 #undef HAVE_SYS_UTSNAME_H
-#undef HAVE_WCHAR_H
-#undef HAVE_WCTYPE_H
 #undef HAVE_TERMCAP_H
 #undef HAVE_TERMIOS_H
 #undef HAVE_TERMIO_H
+#undef HAVE_WCHAR_H
+#undef HAVE_WCTYPE_H
 #undef HAVE_UNISTD_H
 #undef HAVE_UTIL_DEBUG_H
 #undef HAVE_UTIL_MSGI18N_H
diff --git a/src/configure.in b/src/configure.in
index 35ecde3..b98af27 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -2964,52 +2964,10 @@
 	AC_MSG_RESULT(yes); AC_DEFINE(HAVE_SYSCONF),
 	AC_MSG_RESULT(not usable))
 
-dnl Our own version of AC_CHECK_SIZEOF(int); fixes a bug when sizeof() can't
-dnl be printed with "%d", and avoids a warning for cross-compiling.
-
-AC_MSG_CHECKING(size of int)
-AC_CACHE_VAL(ac_cv_sizeof_int,
-	[AC_TRY_RUN([
-#include <stdio.h>
-#if STDC_HEADERS
-# include <stdlib.h>
-# include <stddef.h>
-#endif
-main()
-{
-  FILE *f=fopen("conftestval", "w");
-  if (!f) exit(1);
-  fprintf(f, "%d\n", (int)sizeof(int));
-  exit(0);
-}],
-	    ac_cv_sizeof_int=`cat conftestval`,
-	    AC_MSG_ERROR([failed to determine sizeof(int)]),
-	    AC_MSG_ERROR([failed to compile test program]))])
-AC_MSG_RESULT($ac_cv_sizeof_int)
-AC_DEFINE_UNQUOTED(SIZEOF_INT, $ac_cv_sizeof_int)
-
-dnl Figure out sizeof(time_t) so that it can be used in #ifdef.
-AC_MSG_CHECKING(size of time_t)
-AC_CACHE_VAL(ac_cv_sizeof_time_t,
-	[AC_TRY_RUN([
-#include <stdio.h>
-#if STDC_HEADERS
-# include <stdlib.h>
-# include <stddef.h>
-#endif
-#include <time.h>
-main()
-{
-  FILE *f=fopen("conftestval", "w");
-  if (!f) exit(1);
-  fprintf(f, "%d\n", (int)sizeof(time_t));
-  exit(0);
-}],
-	    ac_cv_sizeof_time_t=`cat conftestval`,
-	    AC_MSG_ERROR([failed to determine sizeof(time_t)]),
-	    AC_MSG_ERROR([failed to compile test program]))])
-AC_MSG_RESULT($ac_cv_sizeof_time_t)
-AC_DEFINE_UNQUOTED(SIZEOF_TIME_T, $ac_cv_sizeof_time_t)
+AC_CHECK_SIZEOF([int])
+AC_CHECK_SIZEOF([long])
+AC_CHECK_SIZEOF([time_t])
+AC_CHECK_SIZEOF([off_t])
 
 dnl Make sure that uint32_t is really 32 bits unsigned.
 AC_MSG_CHECKING([uint32_t is 32 bits])
diff --git a/src/fileio.c b/src/fileio.c
index ff21783..2685101 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -59,7 +59,7 @@
 #endif
 #ifdef FEAT_CRYPT
 static int get_crypt_method __ARGS((char *ptr, int len));
-static char_u *check_for_cryptkey __ARGS((char_u *cryptkey, char_u *ptr, long *sizep, long *filesizep, int newfile, int *did_ask));
+static char_u *check_for_cryptkey __ARGS((char_u *cryptkey, char_u *ptr, long *sizep, off_t *filesizep, int newfile, int *did_ask));
 #endif
 #ifdef UNIX
 static void set_file_time __ARGS((char_u *fname, time_t atime, time_t mtime));
@@ -247,7 +247,7 @@
     colnr_T	len;
     long	size = 0;
     char_u	*p;
-    long	filesize = 0;
+    off_t	filesize = 0;
     int		skip_read = FALSE;
 #ifdef FEAT_CRYPT
     char_u	*cryptkey = NULL;
@@ -2866,7 +2866,7 @@
     char_u	*cryptkey;	/* previous encryption key or NULL */
     char_u	*ptr;		/* pointer to read bytes */
     long	*sizep;		/* length of read bytes */
-    long	*filesizep;	/* nr of bytes used from file */
+    off_t	*filesizep;	/* nr of bytes used from file */
     int		newfile;	/* editing a new buffer */
     int		*did_ask;	/* flag: whether already asked for key */
 {
@@ -5222,7 +5222,7 @@
 msg_add_lines(insert_space, lnum, nchars)
     int	    insert_space;
     long    lnum;
-    long    nchars;
+    off_t   nchars;
 {
     char_u  *p;
 
@@ -5231,7 +5231,13 @@
     if (insert_space)
 	*p++ = ' ';
     if (shortmess(SHM_LINES))
-	sprintf((char *)p, "%ldL, %ldC", lnum, nchars);
+	sprintf((char *)p,
+#ifdef LONG_LONG_OFF_T
+		"%ldL, %lldC",
+#else
+		"%ldL, %ldC",
+#endif
+		lnum, nchars);
     else
     {
 	if (lnum == 1)
@@ -5242,7 +5248,13 @@
 	if (nchars == 1)
 	    STRCPY(p, _("1 character"));
 	else
-	    sprintf((char *)p, _("%ld characters"), nchars);
+	    sprintf((char *)p,
+#ifdef LONG_LONG_OFF_T
+		    _("%lld characters"),
+#else
+		    _("%ld characters"),
+#endif
+		    nchars);
     }
 }
 
@@ -6813,7 +6825,7 @@
 #if defined(FEAT_CON_DIALOG) || defined(FEAT_GUI_DIALOG)
     int		can_reload = FALSE;
 #endif
-    size_t	orig_size = buf->b_orig_size;
+    off_t	orig_size = buf->b_orig_size;
     int		orig_mode = buf->b_orig_mode;
 #ifdef FEAT_GUI
     int		save_mouse_correct = need_mouse_correct;
@@ -7213,7 +7225,7 @@
     char_u	*fname UNUSED;
 {
     buf->b_mtime = (long)st->st_mtime;
-    buf->b_orig_size = (size_t)st->st_size;
+    buf->b_orig_size = st->st_size;
 #ifdef HAVE_ST_MODE
     buf->b_orig_mode = (int)st->st_mode;
 #else
diff --git a/src/memline.c b/src/memline.c
index 6f0143c..d9043dc 100644
--- a/src/memline.c
+++ b/src/memline.c
@@ -1983,7 +1983,7 @@
 	     */
 	    if (mch_stat((char *)buf->b_ffname, &st) == -1
 		    || st.st_mtime != buf->b_mtime_read
-		    || (size_t)st.st_size != buf->b_orig_size)
+		    || st.st_size != buf->b_orig_size)
 	    {
 		ml_preserve(buf, FALSE);
 		did_check_timestamps = FALSE;
diff --git a/src/netbeans.c b/src/netbeans.c
index bd83f64..ff191d7 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -939,7 +939,7 @@
 			char_u *tooltip, char_u *glyphfile,
 			char_u *fg, char_u *bg));
 static void print_read_msg __ARGS((nbbuf_T *buf));
-static void print_save_msg __ARGS((nbbuf_T *buf, long nchars));
+static void print_save_msg __ARGS((nbbuf_T *buf, off_t nchars));
 
 static int curPCtype = -1;
 
@@ -3837,7 +3837,7 @@
     nbbuf_T	*buf;
 {
     int	    lnum = buf->bufp->b_ml.ml_line_count;
-    long    nchars = (long)buf->bufp->b_orig_size;
+    off_t   nchars = buf->bufp->b_orig_size;
     char_u  c;
 
     msg_add_fname(buf->bufp, buf->bufp->b_ffname);
@@ -3873,7 +3873,7 @@
     static void
 print_save_msg(buf, nchars)
     nbbuf_T	*buf;
-    long	nchars;
+    off_t	nchars;
 {
     char_u	c;
     char_u	*p;
@@ -3885,7 +3885,7 @@
 	c = FALSE;
 
 	msg_add_lines(c, buf->bufp->b_ml.ml_line_count,
-						(long)buf->bufp->b_orig_size);
+						buf->bufp->b_orig_size);
 
 	vim_free(keep_msg);
 	keep_msg = NULL;
diff --git a/src/os_win32.h b/src/os_win32.h
index b57ee23..527d8c7 100644
--- a/src/os_win32.h
+++ b/src/os_win32.h
@@ -93,6 +93,7 @@
 
 #include <stdlib.h>
 #include <time.h>
+#include <sys/types.h>
 
 #ifndef STRICT
 # define STRICT
diff --git a/src/proto/fileio.pro b/src/proto/fileio.pro
index 32e3045..75285df 100644
--- a/src/proto/fileio.pro
+++ b/src/proto/fileio.pro
@@ -9,7 +9,7 @@
 int check_file_readonly __ARGS((char_u *fname, int perm));
 int buf_write __ARGS((buf_T *buf, char_u *fname, char_u *sfname, linenr_T start, linenr_T end, exarg_T *eap, int append, int forceit, int reset_changed, int filtering));
 void msg_add_fname __ARGS((buf_T *buf, char_u *fname));
-void msg_add_lines __ARGS((int insert_space, long lnum, long nchars));
+void msg_add_lines __ARGS((int insert_space, long lnum, off_t nchars));
 char_u *shorten_fname1 __ARGS((char_u *full_path));
 char_u *shorten_fname __ARGS((char_u *full_path, char_u *dir_name));
 void shorten_fnames __ARGS((int force));
diff --git a/src/structs.h b/src/structs.h
index 2ec02f3..927aa06 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1200,7 +1200,7 @@
 
     long	b_mtime;	/* last change time of original file */
     long	b_mtime_read;	/* last change time when reading */
-    size_t	b_orig_size;	/* size of original file in bytes */
+    off_t	b_orig_size;	/* size of original file in bytes */
     int		b_orig_mode;	/* mode of original file */
 
     pos_T	b_namedm[NMARKS]; /* current named marks (mark.c) */
diff --git a/src/vim.h b/src/vim.h
index 8ae6856..a5d7364 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -411,6 +411,16 @@
 #define PRINTF_DECIMAL_LONG_U SCANF_DECIMAL_LONG_U
 
 /*
+ * Only systems which use configure will have SIZEOF_OFF_T and SIZEOF_LONG
+ * defined, which is ok since those are the same systems which can have
+ * varying sizes for off_t.  The other systems will continue to use "%ld" to
+ * print off_t since off_t is simply a typedef to long for them.
+ */
+#if defined(SIZEOF_OFF_T) && (SIZEOF_OFF_T > SIZEOF_LONG)
+# define LONG_LONG_OFF_T
+#endif
+
+/*
  * The characters and attributes cached for the screen.
  */
 typedef char_u schar_T;