diff --git a/photobook.cls b/photobook.cls
index ef8e58f..e52ed26 100644
--- a/photobook.cls
+++ b/photobook.cls
@@ -5336,6 +5336,7 @@
 %%
 %%	>>	\pdfspreadstopages[<delta>]{<block-pdf>}
 %%
+% XXX this needs the pdf view mode to be set to single page...
 % XXX do we skip the first/last single pages? ...an option?
 \newcommand\pdfspreadstopages[2][0.3mm]{%
 	\includepdf[pages={{},1-}, nup=2x1, delta=#1 #1]{#2}}