diff --git a/docs/Makefile b/docs/Makefile
index 4aed49fe..dba7408b 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -9,7 +9,7 @@ index.html: ../README-source.adoc Makefile algebras.svg
 	#asciidoctor --trace -r asciidoctor-multipage -b multipage_html5   -D pages $<
 
 %.svg: %.dot
-	dot  -Tsvg $< -o $@
+	dot  -Tsvg $< | sed -E 's/Generated by graphviz .*/Generated by graphviz/'> $@
 
 %.dot: %.dot.m4
 	m4 $< > $@