diff --git a/Makefile b/Makefile
index d3e53c8d91aa80769b176301a5896fd649234b6d..3b39eb514adb1a6f21041b6db1db3f0a170fd3ae 100644
--- a/Makefile
+++ b/Makefile
@@ -21,4 +21,6 @@ clean:
 	*.sls \
 	*.glg \
 	*.gls \
+	*.ind \
+	*.ilg \
 	svg-inkscape