diff --git a/docs/man/nutdrv_qx.txt b/docs/man/nutdrv_qx.txt
index 1948d8e227..a75f3bc6c7 100644
--- a/docs/man/nutdrv_qx.txt
+++ b/docs/man/nutdrv_qx.txt
@@ -800,7 +800,7 @@ The driver is supposed to support both "new" A series (A700/1000/2000/3000 and t
 
 
 VOLTRONIC-AXPERT UNITS
-~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~
 
 This protocol supports Voltronic Power Axpert inverters, based on P30 protocol
 (used e.g. in photovoltaic equipment, often paired with an UPS charged by the