--- docs/doxygen/Doxyfile.in.orig	2020-02-16 18:48:02 UTC
+++ docs/doxygen/Doxyfile.in
@@ -1848,7 +1848,7 @@ DOT_FONTSIZE           = 10
 # If you specify a different font using DOT_FONTNAME you can use DOT_FONTPATH to
 # set the path where dot can find it.
 
-DOT_FONTPATH           =
+DOT_FONTPATH           =	/usr/local/share/fonts/freefont-ttf
 
 # If the CLASS_GRAPH and HAVE_DOT tags are set to YES then doxygen
 # will generate a graph for each documented class showing the direct and
