diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Gpt.c b/MdeModulePkg/Universal/Disk/PartitionDxe/Gpt.c
index 581007e92a..00f5ec06e0 100644
--- a/MdeModulePkg/Universal/Disk/PartitionDxe/Gpt.c
+++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Gpt.c
@@ -366,7 +366,7 @@ PartitionValidGptTable (
     return FALSE;
   }
 
-  if ((PartHdr->Header.Signature == EFI_PTAB_HEADER_ID) ||
+  if ((PartHdr->Header.Signature != EFI_PTAB_HEADER_ID) ||
       !PartitionCheckCrc (BlockSize, &PartHdr->Header) ||
       PartHdr->MyLBA != Lba
       ) {