diff --git a/MdePkg/Include/Library/ReportStatusCodeLib.h b/MdePkg/Include/Library/ReportStatusCodeLib.h
index 65ae20de13..8b71274d73 100644
--- a/MdePkg/Include/Library/ReportStatusCodeLib.h
+++ b/MdePkg/Include/Library/ReportStatusCodeLib.h
@@ -198,6 +198,8 @@ ReportStatusCode (
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate the 
                                  extended data section.
   @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 EFI_STATUS
@@ -240,6 +242,8 @@ ReportStatusCodeWithDevicePath (
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate the 
                                  extended data section.
   @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 EFI_STATUS
@@ -290,7 +294,9 @@ ReportStatusCodeWithExtendedData (
   @retval  EFI_SUCCESS           The status code was reported.
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate 
                                  the extended data section if it was specified.
-  @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_UNSUPPORTED       Report status code is not supported.
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 EFI_STATUS
@@ -405,6 +411,8 @@ ReportDebugCodeEnabled (
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate the 
                                  extended data section.
   @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 #define REPORT_STATUS_CODE_WITH_DEVICE_PATH(Type,Value,DevicePathParameter)                     \
@@ -436,6 +444,8 @@ ReportDebugCodeEnabled (
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate the 
                                  extended data section.
   @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 #define REPORT_STATUS_CODE_WITH_EXTENDED_DATA(Type,Value,ExtendedData,ExtendedDataSize)         \
@@ -472,6 +482,8 @@ ReportDebugCodeEnabled (
   @retval  EFI_OUT_OF_RESOURCES  There were not enough resources to allocate the 
                                  extended data section if it was specified.
   @retval  EFI_UNSUPPORTED       Report status code is not supported
+  @retval  EFI_DEVICE_ERROR      A call to a Report Status Code Library function
+                                 is already in progress.
 
 **/
 #define REPORT_STATUS_CODE_EX(Type,Value,Instance,CallerId,ExtendedDataGuid,ExtendedData,ExtendedDataSize)  \
diff --git a/MdePkg/Include/Library/UefiDecompressLib.h b/MdePkg/Include/Library/UefiDecompressLib.h
index 973fb2ec4d..42af591780 100644
--- a/MdePkg/Include/Library/UefiDecompressLib.h
+++ b/MdePkg/Include/Library/UefiDecompressLib.h
@@ -102,7 +102,7 @@ EFIAPI
 UefiDecompress (
   IN CONST VOID  *Source,
   IN OUT VOID    *Destination,
-  IN OUT VOID    *Scratch
+  IN OUT VOID    *Scratch  OPTIONAL
   );
 
 #endif
diff --git a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
index 18555d1d4f..98492c88f8 100644
--- a/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
+++ b/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c
@@ -738,7 +738,7 @@ EFIAPI
 UefiDecompress (
   IN CONST VOID  *Source,
   IN OUT VOID    *Destination,
-  IN OUT VOID    *Scratch
+  IN OUT VOID    *Scratch  OPTIONAL
   )
 {
   volatile UINT32  Index;