diff --git a/ChangeLog b/ChangeLog
index ea827b2472..37c7eeb114 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Jun 27 13:25:07 2010  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (simple_sendfile): don't try to send data more than SSIZE_MAX
+	  with single sendfile call..
+	  based on the patch by Eric Wong.  [ruby-core:30908]
+
 Sun Jun 27 10:41:38 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/rubygems/require_paths_builder.rb (write_require_paths_file_if_needed):
diff --git a/io.c b/io.c
index 68f6a96522..48634d306b 100644
--- a/io.c
+++ b/io.c
@@ -8078,9 +8078,14 @@ nogvl_copy_stream_wait_write(struct copy_stream_struct *stp)
 #endif
 
 static ssize_t
-simple_sendfile(int out_fd, int in_fd, off_t *offset, size_t count)
+simple_sendfile(int out_fd, int in_fd, off_t *offset, off_t count)
 {
-    return sendfile(out_fd, in_fd, offset, count);
+#if SIZEOF_OFF_T > SIZEOF_SIZE_T
+    /* we are limited by the 32-bit ssize_t return value on 32-bit */
+    if (count > (off_t)SSIZE_MAX)
+        count = SSIZE_MAX;
+#endif
+    return sendfile(out_fd, in_fd, offset, (size_t)count);
 }
 
 #endif