diff --git a/UefiCpuPkg/CpuDxe/CpuMp.c b/UefiCpuPkg/CpuDxe/CpuMp.c
index 44569466d3..372c1e3ce4 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.c
+++ b/UefiCpuPkg/CpuDxe/CpuMp.c
@@ -412,7 +412,7 @@ StartupThisAP (
   @retval EFI_UNSUPPORTED         Switching the BSP cannot be completed prior to
                                   this service returning.
   @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
-  @retval EFI_SUCCESS             The calling processor is an AP.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
   @retval EFI_NOT_FOUND           The processor with the handle specified by
                                   ProcessorNumber does not exist.
   @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the current BSP or
diff --git a/UefiCpuPkg/CpuDxe/CpuMp.h b/UefiCpuPkg/CpuDxe/CpuMp.h
index 43ec3bdd0b..d530149d7e 100644
--- a/UefiCpuPkg/CpuDxe/CpuMp.h
+++ b/UefiCpuPkg/CpuDxe/CpuMp.h
@@ -375,7 +375,7 @@ StartupThisAP (
   @retval EFI_UNSUPPORTED         Switching the BSP cannot be completed prior to
                                   this service returning.
   @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
-  @retval EFI_SUCCESS             The calling processor is an AP.
+  @retval EFI_DEVICE_ERROR        The calling processor is an AP.
   @retval EFI_NOT_FOUND           The processor with the handle specified by
                                   ProcessorNumber does not exist.
   @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the current BSP or