diff --git a/doc/source/firmware.rst b/doc/source/firmware.rst
index 37064a448c069c4ea693aade62a8cb196010cd61..eae634a11b2cc383d88fbbbf519a3539735a9d19 100644
--- a/doc/source/firmware.rst
+++ b/doc/source/firmware.rst
@@ -501,7 +501,7 @@ Writing any byte to this command triggers a uC reset.
 .. _UPTIME_SECS:
 
 (ext.) UPTIME_SECS
-~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~
 
 | Ext. Command code: **10**
 | Transaction type: **Word read**