diff --git a/MdePkg/Library/UefiLib/Acpi.c b/MdePkg/Library/UefiLib/Acpi.c
index 4df6731ff0..59a828835c 100644
--- a/MdePkg/Library/UefiLib/Acpi.c
+++ b/MdePkg/Library/UefiLib/Acpi.c
@@ -67,7 +67,7 @@ ScanTableInSDT (
     EntryPtr = 0;
     CopyMem (&EntryPtr, (VOID *)(BasePtr + Index * TablePointerSize), TablePointerSize);
     Table = (EFI_ACPI_COMMON_HEADER *)((UINTN)(EntryPtr));
-    if (Table->Signature == Signature) {
+    if ((Table != NULL) && (Table->Signature == Signature)) {
       if (PreviousTable != NULL) {
         if (Table == PreviousTable) {
           *PreviousTableLocated = TRUE;