diff --git a/src/doc/doxygen.cfg.in b/src/doc/doxygen.cfg.in
index 6dd9f30c6b..0907011bbb 100644
--- a/src/doc/doxygen.cfg.in
+++ b/src/doc/doxygen.cfg.in
@@ -1682,7 +1682,7 @@ DOT_NUM_THREADS        = 0
 # the DOTFONTPATH environment variable or by setting DOT_FONTPATH to the
 # directory containing the font.
 
-DOT_FONTNAME           = FreeSans
+DOT_FONTNAME           =
 
 # The DOT_FONTSIZE tag can be used to set the size of the font of dot graphs.
 # The default size is 10pt.