diff --git a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
index c17daa0fc0..b2307cbb61 100644
--- a/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
+++ b/UefiCpuPkg/Library/MpInitLib/DxeMpLib.c
@@ -236,7 +236,6 @@ GetProtectedModeCS (
   UINTN                    GdtEntryCount;
   UINT16                   Index;
 
-  Index = (UINT16) -1;
   AsmReadGdtr (&GdtrDesc);
   GdtEntryCount = (GdtrDesc.Limit + 1) / sizeof (IA32_SEGMENT_DESCRIPTOR);
   GdtEntry = (IA32_SEGMENT_DESCRIPTOR *) GdtrDesc.Base;
@@ -248,7 +247,7 @@ GetProtectedModeCS (
     }
     GdtEntry++;
   }
-  ASSERT (Index != -1);
+  ASSERT (Index != GdtEntryCount);
   return Index * 8;
 }