diff -r 777256817c1b Lib/test/test_io.py
--- a/Lib/test/test_io.py	Thu Aug 04 12:14:51 2016 -0500
+++ b/Lib/test/test_io.py	Thu Aug 04 19:58:21 2016 +0200
@@ -561,6 +561,24 @@
         with self.open(support.TESTFN, "w+b") as f:
             self.large_file_ops(f)
 
+    def test_large_writes(self):
+        support.requires('largefile',
+            'test requires %s bytes and a long time to run' % self.LARGE)
+        with self.open(support.TESTFN, "wb") as f:
+            b = bytearray(self.LARGE)
+            self.assertEqual(f.write(b), self.LARGE)
+
+    def test_large_reads(self):
+        support.requires('largefile',
+            'test requires %s bytes and a long time to run' % self.LARGE)
+        with self.open(support.TESTFN, "wb") as f:
+            b = bytearray(self.LARGE)
+            self.assertEqual(f.write(b), self.LARGE)
+
+        with self.open(support.TESTFN, "rb") as f:
+            self.assertEqual(f.read(self.LARGE), self.LARGE)
+
+
     def test_with_open(self):
         for bufsize in (0, 1, 100):
             f = None
diff -r 777256817c1b Python/fileutils.c
--- a/Python/fileutils.c	Thu Aug 04 12:14:51 2016 -0500
+++ b/Python/fileutils.c	Thu Aug 04 19:58:21 2016 +0200
@@ -1203,6 +1203,13 @@
         /* On Windows, the count parameter of read() is an int */
         count = INT_MAX;
     }
+#elif defined(__APPLE__)
+    if (count > INT_MAX) {
+        /* Issue #24658: On OSX read(2) will fail when reading more than INT_MAX
+         * bytes.
+         */
+        count = INT_MAX;
+    }
 #else
     if (count > PY_SSIZE_T_MAX) {
         /* if count is greater than PY_SSIZE_T_MAX,
@@ -1272,6 +1279,12 @@
     }
     else if (count > INT_MAX)
         count = INT_MAX;
+#elif defined(__APPLE__)
+    if (count > INT_MAX) {
+        /* Issue #24658: On OSX write(2) will fail when writing more than
+           INT_MAX bytes. */
+        count = INT_MAX;
+    }
 #else
     if (count > PY_SSIZE_T_MAX) {
         /* write() should truncate count to PY_SSIZE_T_MAX, but it's safer