diff --git a/lib/make/mb_openmsx.mk b/lib/make/mb_openmsx.mk
index 07f0730..3bd145d 100644
--- a/lib/make/mb_openmsx.mk
+++ b/lib/make/mb_openmsx.mk
@@ -51,7 +51,6 @@ define _mb_openmsx_run
 		-script $(PATH_MSXBUILD_REAL)/lib/openmsx/boot_hdd.tcl \
 		-script $(PATH_MSXBUILD_REAL)/lib/openmsx/fail_after.tcl \
 		-setting $(PATH_MSXBUILD_REAL)/lib/openmsx/boot_setting.xml \
-		-command "set sound_driver null" \
 	-control stdio < $(PATH_MSXBUILD_REAL)/lib/openmsx/boot_stdio.xml
 endef
 
diff --git a/lib/openmsx/boot_env.tcl b/lib/openmsx/boot_env.tcl
index ec3da45..41e2c77 100644
--- a/lib/openmsx/boot_env.tcl
+++ b/lib/openmsx/boot_env.tcl
@@ -6,6 +6,9 @@
 # SAVE_SETTINGS_ON_EXIT=off
 # Disables automatic settings saving.
 #
+# SOUND_DRIVER=null
+# Disabled sound to remove boot beeps.
+#
 # RENDERER=SDL
 # Override video output from command line.
 #
diff --git a/lib/openmsx/boot_stdio.xml b/lib/openmsx/boot_stdio.xml
index c49ca68..6cfb7ca 100644
--- a/lib/openmsx/boot_stdio.xml
+++ b/lib/openmsx/boot_stdio.xml
@@ -3,6 +3,5 @@
 When booting 'openmsx -control stdio < boot_stdio.xml'
 It starts then in power off mode and without renderer for fast booting.
 -->
-	<command>set sound_driver null</command>
 	<command>set power on</command>
 </openmsx-control>