diff --git a/docs/programming-guide.md b/docs/programming-guide.md
index 97bcb511b2b02b4c81da0df3316b4e13d195d8ca..3872aecff25d781f48d61b517694c85485dec9dc 100644
--- a/docs/programming-guide.md
+++ b/docs/programming-guide.md
@@ -1220,6 +1220,11 @@ storage levels is:
   <td> MEMORY_ONLY_2, MEMORY_AND_DISK_2, etc.  </td>
   <td> Same as the levels above, but replicate each partition on two cluster nodes. </td>
 </tr>
+<tr>
+  <td> OFF_HEAP (experimental) </td>
+  <td> Similar to MEMORY_ONLY_SER, but store the data in
+    <a href="configuration.html#memory-management">off-heap memory</a>. This requires off-heap memory to be enabled. </td>
+</tr>
 </table>
 
 **Note:** *In Python, stored objects will always be serialized with the [Pickle](https://docs.python.org/2/library/pickle.html) library,