diff --git a/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAA b/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAA
index f008815cc90..e1e031ab739 100644
--- a/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAA
+++ b/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAA
@@ -28,4 +28,7 @@ config SRAM_SIZE
 config FLASH_SIZE
 	default 256
 
+config ISR_STACK_SIZE
+	default 640
+
 endif # SOC_NRF51822_QFAA
diff --git a/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAB b/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAB
index b23a548b344..be53d0c6ebe 100644
--- a/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAB
+++ b/arch/arm/soc/nordic_nrf5/nrf51/Kconfig.defconfig.nrf51822_QFAB
@@ -28,4 +28,7 @@ config SRAM_SIZE
 config FLASH_SIZE
 	default 128
 
+config ISR_STACK_SIZE
+	default 640
+
 endif # SOC_NRF51822_QFAB