diff --git a/src/mainboard/google/rush_ryu/Kconfig b/src/mainboard/google/rush_ryu/Kconfig
index 192b9faead..ec6eadb86b 100644
--- a/src/mainboard/google/rush_ryu/Kconfig
+++ b/src/mainboard/google/rush_ryu/Kconfig
@@ -31,6 +31,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select MAINBOARD_HAS_BOOTBLOCK_INIT
 	select BOARD_ROMSIZE_KB_4096
 	select VIRTUAL_DEV_SWITCH
+	select TERTIARY_BOARD_ID
 
 config MAINBOARD_DIR
 	string
diff --git a/src/mainboard/google/rush_ryu/boardid.c b/src/mainboard/google/rush_ryu/boardid.c
index 67e55ba3fb..42a51bd0cf 100644
--- a/src/mainboard/google/rush_ryu/boardid.c
+++ b/src/mainboard/google/rush_ryu/boardid.c
@@ -19,6 +19,7 @@
 
 #include <console/console.h>
 #include <soc/nvidia/tegra132/gpio.h>
+#include <stdlib.h>
 
 #include <boardid.h>
 
@@ -27,12 +28,11 @@ uint8_t board_id(void)
 	static int id = -1;
 
 	if (id < 0) {
-		id = gpio_get_in_value(GPIO(Q3)) << 0 |
-		     gpio_get_in_value(GPIO(T1)) << 1 |
-		     gpio_get_in_value(GPIO(X1)) << 2 |
-		     gpio_get_in_value(GPIO(X4)) << 3;
-		printk(BIOS_SPEW, "Board ID: %#x.\n", id);
-	}
+		gpio_t gpio[] = {GPIO(Q3), GPIO(Q4)};
 
+		id = gpio_get_in_tristate_values(gpio, ARRAY_SIZE(gpio), 0);
+
+		printk(BIOS_SPEW, "Board TRISTATE ID: %#x.\n", id);
+	}
 	return id;
 }