diff --git a/src/mainboard/google/guybrush/Kconfig b/src/mainboard/google/guybrush/Kconfig
index c259d25fb5..e5f138258f 100644
--- a/src/mainboard/google/guybrush/Kconfig
+++ b/src/mainboard/google/guybrush/Kconfig
@@ -111,6 +111,22 @@ config NORMAL_READ_SPI_SPEED
 config ALT_SPI_SPEED
 	default 0	# 66MHz
 
+config OVERRIDE_EFS_SPI_SPEED
+	int
+	default 3 if EM100
+	default 4	# 100MHz
+	help
+	  Override EFS SPI Speed Configuration to be applied based on certain
+	  board version.
+
+config OVERRIDE_EFS_SPI_SPEED_MIN_BOARD
+	hex
+	default 0x4 if BOARD_GOOGLE_GUYBRUSH
+	default 0xffffffff
+	help
+	  Minimum board version starting which the Override EFS SPI Speed
+	  configuration has to be applied.
+
 endif # !EM100
 
 config VARIANT_DIR
diff --git a/src/mainboard/google/guybrush/Makefile.inc b/src/mainboard/google/guybrush/Makefile.inc
index f3140ddbdb..6bc3288276 100644
--- a/src/mainboard/google/guybrush/Makefile.inc
+++ b/src/mainboard/google/guybrush/Makefile.inc
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
 bootblock-y += bootblock.c
+bootblock-$(CONFIG_CHROMEOS) += chromeos.c
 
 ifneq ($(wildcard $(MAINBOARD_BLOBS_DIR)/APCB_CZN_D4.bin),)
 $(info APCB sources present.)
diff --git a/src/mainboard/google/guybrush/chromeos.c b/src/mainboard/google/guybrush/chromeos.c
index c1621d917e..a43b3032bb 100644
--- a/src/mainboard/google/guybrush/chromeos.c
+++ b/src/mainboard/google/guybrush/chromeos.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 
+#include <amdblocks/spi.h>
 #include <baseboard/gpio.h>
 #include <boardid.h>
 #include <boot/coreboot_tables.h>
@@ -36,3 +37,11 @@ int get_ec_is_trusted(void)
 	/* EC is trusted if not in RW. */
 	return !gpio_get(GPIO_EC_IN_RW);
 }
+
+void mainboard_spi_fast_speed_override(uint8_t *fast_speed)
+{
+	uint32_t board_ver = board_id();
+
+	if (board_ver >= CONFIG_OVERRIDE_EFS_SPI_SPEED_MIN_BOARD)
+		*fast_speed = CONFIG_OVERRIDE_EFS_SPI_SPEED;
+}