diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 6fecaf5..c06b757 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -41,6 +41,10 @@
             self.assertEqual(m[0], '\0')
             self.assertEqual(m[0:3], '\0\0\0')
 
+            # Shouldn't crash on boundary (Issue #5292)
+            self.assertRaises(IndexError, m.__getitem__, len(m))
+            self.assertRaises(IndexError, m.__setitem__, len(m), '\0')
+
             # Modify the file's content
             m[0] = '3'
             m[PAGESIZE +3: PAGESIZE +3+3] = 'bar'
@@ -413,6 +417,27 @@
             m = mmap.mmap(f.fileno(), mapsize - halfsize, offset=halfsize)
             self.assertEqual(m[0:3], 'foo')
             f.close()
+
+            # Try resizing map
+            try:
+                m.resize(512)
+            except SystemError:
+                pass
+            else:
+                # resize() is supported
+                self.assertEqual(len(m), 512)
+                # Check that we can no longer seek beyond the new size.
+                self.assertRaises(ValueError, m.seek, 513, 0)
+                # Check that the content is not changed
+                self.assertEqual(m[0:3], 'foo')
+
+                # Check that the underlying file is truncated too
+                f = open(TESTFN)
+                f.seek(0, 2)
+                self.assertEqual(f.tell(), halfsize + 512)
+                f.close()
+                self.assertEqual(m.size(), halfsize + 512)
+
             m.close()
 
         finally: