diff --git a/doc/Makefile.am b/doc/Makefile.am
index 4a8cdd3b2bdd5485b6440a8a7e045f99daa9bdcc..7ebe62c0baa25f73fe20a0c0b899f8a376d79a23 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -81,7 +81,7 @@ $(GUIDE).html: $(IMAGES) $(GUIDE_TEXIFILES)
 	mv -f "$$TMP_FILE" "$$INDEX_FILE"
 
 $(GUIDE).pdf: $(IMAGES) $(GUIDE_TEXIFILES)
-	$(TEXI2PDF) $(srcdir)/$(GUIDE).texi
+	-$(TEXI2PDF) $(srcdir)/$(GUIDE).texi
 
 clean-local:
 	rm -f *.aux *.log *.dvi *.info *.tmp