diff --git a/lib/make/mb_openmsx.mk b/lib/make/mb_openmsx.mk
index 3bd145d..58ed983 100644
--- a/lib/make/mb_openmsx.mk
+++ b/lib/make/mb_openmsx.mk
@@ -15,7 +15,6 @@ MB_OPENMSX_THROTTLE     ?= off
 MB_OPENMSX_RENDERER     ?=
 MB_OPENMSX_CTLCACHE     ?= $(MB_CACHE)/omsxctl
 MB_OPENMSX_SAVE_ON_EXIT ?= off
-MB_OPENMSX_SOUND_DRIVER ?= null
 
 # TODO: create openMSX issue to clean share: https://github.com/openMSX/openMSX/issues/1672
 define _mb_openmsx_setup
diff --git a/lib/openmsx/boot_env.tcl b/lib/openmsx/boot_env.tcl
index 41e2c77..70edb9b 100644
--- a/lib/openmsx/boot_env.tcl
+++ b/lib/openmsx/boot_env.tcl
@@ -6,9 +6,6 @@
 # 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.
 #
@@ -35,13 +32,6 @@ if {[info exists ::env(SAVE_SETTINGS_ON_EXIT)] && ([string trim $::env(SAVE_SETT
 	}
 }
 
-if {[info exists ::env(SOUND_DRIVER)] && ([string trim $::env(SOUND_DRIVER)] != "")} {
-	if {[catch {set sound_driver [string trim $::env(SOUND_DRIVER)]} err_msg]} {
-		puts stderr "error: env.SOUND_DRIVER value $err_msg"
-		exit 1
-	}
-}
-
 if {[info exists ::env(RENDERER)] && ([string trim $::env(RENDERER)] != "")} {
 	if {[catch {set renderer [string trim $::env(RENDERER)]} err_msg]} {
 		puts stderr "error: env.RENDERER value $err_msg"