diff --git a/doc/userman/Makefile b/doc/userman/Makefile
index 7a4612fbc61de71fc0681ae07b829ecaaf1395ef..4aecdea8e95a26e94731deac2caa25b0b366ccb5 100644
--- a/doc/userman/Makefile
+++ b/doc/userman/Makefile
@@ -60,11 +60,7 @@ version.tex: Makefile
 	ocamllex $<
 
 %.pdf: %.tex
-	pdflatex $*
-	makeindex $*
-	bibtex $*
-	pdflatex $*
-	pdflatex $*
+	latexmk $<
 
 %.cmo: %.ml
 	ocamlc -c $<