diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h
index 9e2aebcfd5..4f42c56a48 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdog.h
@@ -20,7 +20,8 @@
 // Control Frame:
 #define GENERIC_WDOG_CONTROL_STATUS_REG       ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x000)
 #define GENERIC_WDOG_OFFSET_REG               ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x008)
-#define GENERIC_WDOG_COMPARE_VALUE_REG        ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x010)
+#define GENERIC_WDOG_COMPARE_VALUE_REG_LOW    ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x010)
+#define GENERIC_WDOG_COMPARE_VALUE_REG_HIGH   ((UINTN)FixedPcdGet64 (PcdGenericWatchdogControlBase) + 0x014)
 
 // Values of bit 0 of the Control/Status Register
 #define GENERIC_WDOG_ENABLED          1
diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
index 3180f01125..8ccf15366d 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
@@ -56,7 +56,8 @@ WatchdogWriteCompareRegister (
   UINT64  Value
   )
 {
-  MmioWrite64 (GENERIC_WDOG_COMPARE_VALUE_REG, Value);
+  MmioWrite32 (GENERIC_WDOG_COMPARE_VALUE_REG_LOW, Value & MAX_UINT32);
+  MmioWrite32 (GENERIC_WDOG_COMPARE_VALUE_REG_HIGH, (Value >> 32) & MAX_UINT32);
 }
 
 VOID