diff --git a/Makefile b/Makefile
index 73f9f95..de08257 100644
--- a/Makefile
+++ b/Makefile
@@ -195,6 +195,8 @@ $(error Invalid target: T=$(T))
 endif
 export T
 
+# Default audio source: en (English, config/_default_cfg_src_/res/en)
+AUDIO ?= en
 # Select audio source
 AUDIO_FOLDER = config/_default_cfg_src_/res/$(AUDIO)
 ifeq ($(AUDIO),)
diff --git a/build.sh b/build.sh
index 9b46afa..3211718 100755
--- a/build.sh
+++ b/build.sh
@@ -1,8 +1,5 @@
 #!/bin/bash
 
-# use AUDIO environment variable, default to "en"
-AUDIO="${AUDIO:-en}"
-
 make -j T=open_source DEBUG=1 >log.txt 2>&1
 
 if [ $? -eq 0 ]; then