diff --git a/docs/reference/ImageShow.rst b/docs/reference/ImageShow.rst
index 45b50c8469b..f5c803b4383 100644
--- a/docs/reference/ImageShow.rst
+++ b/docs/reference/ImageShow.rst
@@ -23,6 +23,9 @@ All default viewers convert the image to be shown to PNG format.
     .. autoclass:: PIL.ImageShow.EogViewer
     .. autoclass:: PIL.ImageShow.XVViewer
 
+    To provide maximum functionality, temporary files created from images will not be
+    automatically removed on Unix-based systems.
+
 .. autofunction:: PIL.ImageShow.register
 .. autoclass:: PIL.ImageShow.Viewer
     :member-order: bysource