diff --git a/README.md b/README.md
index 9ea5b85..c5fd763 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,7 @@ convert score.png -rotate 90 score.pdf
 # Split the PDF up into multiple pages for the printer
 # -s1	Don't scale the output
 # -m	Sets the output paper size. Defaults to A4 (21x29.7cm) if unspecified, but may need to reduce by a cm or 2 on each side (as below) if things get cut off.
-pdfposter -s1 -m 20x28.7cm score.pdf print.pdf
+pdfposter -s1 -m 20x27.7cm score.pdf print.pdf
 ```
 
 ....if that cuts things off at the edges, try doing it like this: