diff --git a/doc/Makefile.am b/doc/Makefile.am
index 2504425..99ea169 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -5,11 +5,14 @@ EXTRA_DIST = ikarus-users-guide.tex ikarus-users-guide.bib ikarus-users-guide.pd
 TEX=xelatex -output-driver="xdvipdfmx -q -E" 
 
 ikarus-users-guide.pdf: ikarus-users-guide.tex ikarus-users-guide.bib
-	$(TEX) ikarus-users-guide
-	makeindex ikarus-users-guide
-	bibtex ikarus-users-guide
-	$(TEX) ikarus-users-guide
-	$(TEX) ikarus-users-guide
+	if test -x "`which xelatex`" ; \
+	then \
+	  $(TEX) ikarus-users-guide && \
+	  makeindex ikarus-users-guide && \
+	  bibtex ikarus-users-guide && \
+	  $(TEX) ikarus-users-guide && \
+	  $(TEX) ikarus-users-guide ; \
+	fi 
 
 all: ikarus-users-guide.pdf
 
diff --git a/doc/Makefile.in b/doc/Makefile.in
index 9e6b22c..d330867 100644
--- a/doc/Makefile.in
+++ b/doc/Makefile.in
@@ -338,11 +338,14 @@ uninstall-am: uninstall-dist_docDATA
 
 
 ikarus-users-guide.pdf: ikarus-users-guide.tex ikarus-users-guide.bib
-	$(TEX) ikarus-users-guide
-	makeindex ikarus-users-guide
-	bibtex ikarus-users-guide
-	$(TEX) ikarus-users-guide
-	$(TEX) ikarus-users-guide
+	if test -x "`which xelatex`" ; \
+	then \
+	  $(TEX) ikarus-users-guide && \
+	  makeindex ikarus-users-guide && \
+	  bibtex ikarus-users-guide && \
+	  $(TEX) ikarus-users-guide && \
+	  $(TEX) ikarus-users-guide ; \
+	fi 
 
 all: ikarus-users-guide.pdf
 
diff --git a/doc/ikarus-users-guide.pdf b/doc/ikarus-users-guide.pdf
index 0c40f1f..a9c2513 100644
Binary files a/doc/ikarus-users-guide.pdf and b/doc/ikarus-users-guide.pdf differ
diff --git a/scheme/last-revision b/scheme/last-revision
index 4872852..b1e1a0c 100644
--- a/scheme/last-revision
+++ b/scheme/last-revision
@@ -1 +1 @@
-1119
+1120