diff --git a/ArmPkg/Drivers/ArmScmiDxe/ScmiClockProtocol.c b/ArmPkg/Drivers/ArmScmiDxe/ScmiClockProtocol.c
index c66c414385..5c06e31bda 100644
--- a/ArmPkg/Drivers/ArmScmiDxe/ScmiClockProtocol.c
+++ b/ArmPkg/Drivers/ArmScmiDxe/ScmiClockProtocol.c
@@ -255,22 +255,26 @@ ClockDescribeRates (
       for (RateNo = 0; RateNo < NUM_RATES (DescribeRates->NumRatesFlags); RateNo++) {
         Rate = &DescribeRates->Rates[RateOffset++];
         // Non-linear discrete rates.
-        RateArray[RateIndex++].Rate = ConvertTo64Bit (Rate->Low, Rate->High);
+        RateArray[RateIndex++].DiscreteRate.Rate =
+          ConvertTo64Bit (Rate->Low, Rate->High);
       }
     } else {
       for (RateNo = 0; RateNo < NUM_RATES (DescribeRates->NumRatesFlags); RateNo++) {
         // Linear clock rates from minimum to maximum in steps
         // Minimum clock rate.
         Rate = &DescribeRates->Rates[RateOffset++];
-        RateArray[RateIndex].Min = ConvertTo64Bit (Rate->Low, Rate->High);
+        RateArray[RateIndex].ContinuousRate.Min =
+          ConvertTo64Bit (Rate->Low, Rate->High);
 
         Rate = &DescribeRates->Rates[RateOffset++];
         // Maximum clock rate.
-        RateArray[RateIndex].Max = ConvertTo64Bit (Rate->Low, Rate->High);
+        RateArray[RateIndex].ContinuousRate.Max =
+          ConvertTo64Bit (Rate->Low, Rate->High);
 
         Rate = &DescribeRates->Rates[RateOffset++];
         // Step.
-        RateArray[RateIndex++].Step = ConvertTo64Bit (Rate->Low, Rate->High);
+        RateArray[RateIndex++].ContinuousRate.Step =
+          ConvertTo64Bit (Rate->Low, Rate->High);
       }
     }
   } while (NUM_REMAIN_RATES (DescribeRates->NumRatesFlags) != 0);
diff --git a/ArmPkg/Include/Protocol/ArmScmiClockProtocol.h b/ArmPkg/Include/Protocol/ArmScmiClockProtocol.h
index b4d970dee3..85b5b8d1e7 100644
--- a/ArmPkg/Include/Protocol/ArmScmiClockProtocol.h
+++ b/ArmPkg/Include/Protocol/ArmScmiClockProtocol.h
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2017-2018, Arm Limited. All rights reserved.
+  Copyright (c) 2017-2021, Arm Limited. All rights reserved.
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -57,12 +57,18 @@ typedef enum {
    either Rate or Min/Max/Step triplet is valid.
 */
 typedef struct {
-  union {
   UINT64 Min;
-  UINT64 Rate;
-  };
   UINT64 Max;
   UINT64 Step;
+} SCMI_CLOCK_RATE_CONTINUOUS;
+
+typedef struct {
+  UINT64 Rate;
+} SCMI_CLOCK_RATE_DISCRETE;
+
+typedef union {
+  SCMI_CLOCK_RATE_CONTINUOUS ContinuousRate;
+  SCMI_CLOCK_RATE_DISCRETE DiscreteRate;
 } SCMI_CLOCK_RATE;
 
 #pragma pack()