diff --git a/createpng b/createpng
index 2f045eb..f2c9d6f 100755
--- a/createpng
+++ b/createpng
@@ -1,5 +1,11 @@
 #!/usr/bin/env bash
 
+#
+# Note: You have to add the following line in /etc/ImageMagick-6/policy.xml:
+#
+# <policy domain="coder" rights="read|write" pattern="PDF,PS" />
+#
+
 PDF="$(ls hacking_tools_cheat_sheet_v*.pdf)"
 PNG="$(sed 's/\.pdf$/.png/' <<< $PDF)"