diff --git a/doc/tutorials/external_memory.rst b/doc/tutorials/external_memory.rst
index 3541b0d21..f4cb9857f 100644
--- a/doc/tutorials/external_memory.rst
+++ b/doc/tutorials/external_memory.rst
@@ -13,9 +13,7 @@ The external memory version takes in the following filename format:
 The ``filename`` is the normal path to libsvm file you want to load in, and ``cacheprefix`` is a
 path to a cache file that XGBoost will use for external memory cache.
 
-.. note:: External memory is not available with GPU algorithms
-
-  External memory is not available when ``tree_method`` is set to ``gpu_hist``.
+.. note:: External memory is also available with GPU algorithms (i.e. when ``tree_method`` is set to ``gpu_hist``)
 
 The following code was extracted from `demo/guide-python/external_memory.py <https://github.com/dmlc/xgboost/blob/master/demo/guide-python/external_memory.py>`_: