diff --git a/src/mainboard/google/rex/Kconfig b/src/mainboard/google/rex/Kconfig
index ceab29e..8d89d2b 100644
--- a/src/mainboard/google/rex/Kconfig
+++ b/src/mainboard/google/rex/Kconfig
@@ -48,6 +48,7 @@
 config BOARD_GOOGLE_MODEL_REX
 	def_bool n
 	select BOARD_GOOGLE_BASEBOARD_REX
+	select CHROMEOS_WIFI_SAR if CHROMEOS
 	select DRIVERS_GENERIC_MAX98357A
 	select DRIVERS_GENESYSLOGIC_GL9755
 	select DRIVERS_INTEL_ISH
diff --git a/src/mainboard/google/rex/variants/rex0/variant.c b/src/mainboard/google/rex/variants/rex0/variant.c
index 6641d4b..2441f96 100644
--- a/src/mainboard/google/rex/variants/rex0/variant.c
+++ b/src/mainboard/google/rex/variants/rex0/variant.c
@@ -12,7 +12,7 @@
 
 const char *get_wifi_sar_cbfs_filename(void)
 {
-	return "wifi_sar_0.hex";
+	return get_wifi_sar_fw_config_filename(FW_CONFIG_FIELD(WIFI));
 }
 
 void variant_generate_s0ix_hook(enum s0ix_entry entry)