diff --git a/doc/src/sgml/docguide.sgml b/doc/src/sgml/docguide.sgml
index 090ca958350..b4338e0e73d 100644
--- a/doc/src/sgml/docguide.sgml
+++ b/doc/src/sgml/docguide.sgml
@@ -336,11 +336,11 @@ checking for fop... fop
file ~/.foprc, for example:
# FOP binary distribution
-FOP_OPTS='-Xmx1000m'
+FOP_OPTS='-Xmx1500m'
# Debian
-JAVA_ARGS='-Xmx1000m'
+JAVA_ARGS='-Xmx1500m'
# Red Hat
-ADDITIONAL_FLAGS='-Xmx1000m'
+ADDITIONAL_FLAGS='-Xmx1500m'
There is a minimum amount of memory that is required, and to some extent
more memory appears to make things a bit faster. On systems with very