diff --git a/Makefile b/Makefile
index 07ba2cd..8881fbd 100644
--- a/Makefile
+++ b/Makefile
@@ -230,6 +230,8 @@ ifeq ($(ENABLE_FEAT_F4HWN),1)
 
 	AUTHOR_STRING ?= $(AUTHOR_STRING_1)+$(AUTHOR_STRING_2)
 	VERSION_STRING ?= $(VERSION_STRING_2)
+
+	SQL_TONE ?= 550 # For SA818, use 600 and python3 sa818.py --port /dev/ttyS2 radio --frequency 434.975 --ctcss 71.9 --tail Open
 else
 	AUTHOR_STRING ?= EGZUMER
 	# the user might not have/want git installed
@@ -412,7 +414,7 @@ endif
 ifeq ($(ENABLE_FEAT_F4HWN),1)
 	CFLAGS  += -DENABLE_FEAT_F4HWN
 	CFLAGS  += -DALERT_TOT=10
-	CFLAGS  += -DSQL_TONE=550 # For SA818, use 600 and python3 sa818.py --port /dev/ttyS2 radio --frequency 434.975 --ctcss 71.9 --tail Open
+	CFLAGS  += -DSQL_TONE=$(SQL_TONE)
 	CFLAGS  += -DAUTHOR_STRING_1=\"$(AUTHOR_STRING_1)\" -DVERSION_STRING_1=\"$(VERSION_STRING_1)\"
 	CFLAGS  += -DAUTHOR_STRING_2=\"$(AUTHOR_STRING_2)\" -DVERSION_STRING_2=\"$(VERSION_STRING_2)\"
 	CFLAGS  += -DEDITION_STRING=\"$(EDITION_STRING)\"