diff --git a/doc/Doxyfile b/doc/Doxyfile
index 45ca8822b..7af897b80 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -1,4 +1,4 @@
-# Doxyfile 1.9.0
+# Doxyfile 1.9.1
 
 #---------------------------------------------------------------------------
 # Project related configuration options