diff --git a/docs/latex/wx/fs_mem.tex b/docs/latex/wx/fs_mem.tex
index 41a02f0d88..fa28cf8300 100644
--- a/docs/latex/wx/fs_mem.tex
+++ b/docs/latex/wx/fs_mem.tex
@@ -87,6 +87,8 @@ data (bitmap, text or raw data)
 will be copied into private memory stream and available under 
 name "memory:" + filename.
 
+Note that when storing image/bitmap, you must use image format that wxWindows
+can write (e.g. JPG, PNG, see \helpref{wxImage documentation}{wximage})!
 
 
 \membersection{wxMemoryFSHandler::RemoveFile}\label{wxmemoryfshandlerremovefile}