diff --git a/BaseTools/Source/C/GenFw/GenFw.c b/BaseTools/Source/C/GenFw/GenFw.c
index 246deb0344..af60c92763 100644
--- a/BaseTools/Source/C/GenFw/GenFw.c
+++ b/BaseTools/Source/C/GenFw/GenFw.c
@@ -2815,6 +2815,7 @@ Returns:
   // Resource Directory entry need to review.
   //
   Optional32Hdr = (EFI_IMAGE_OPTIONAL_HEADER32 *) ((UINT8*) FileHdr + sizeof (EFI_IMAGE_FILE_HEADER));
+  Optional64Hdr = (EFI_IMAGE_OPTIONAL_HEADER64 *) ((UINT8*) FileHdr + sizeof (EFI_IMAGE_FILE_HEADER));
   if (Optional32Hdr->Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
     SectionHeader = (EFI_IMAGE_SECTION_HEADER *) ((UINT8 *) Optional32Hdr +  FileHdr->SizeOfOptionalHeader);
     if (Optional32Hdr->NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_EXPORT && \
@@ -2835,7 +2836,6 @@ Returns:
       }
     }
   } else {
-    Optional64Hdr = (EFI_IMAGE_OPTIONAL_HEADER64 *) ((UINT8*) FileHdr + sizeof (EFI_IMAGE_FILE_HEADER));
     SectionHeader = (EFI_IMAGE_SECTION_HEADER *) ((UINT8 *) Optional64Hdr +  FileHdr->SizeOfOptionalHeader);
     if (Optional64Hdr->NumberOfRvaAndSizes > EFI_IMAGE_DIRECTORY_ENTRY_EXPORT && \
         Optional64Hdr->DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_EXPORT].Size != 0) {
@@ -2909,6 +2909,16 @@ Returns:
           RsdsEntry->Unknown3 = 0;
           RsdsEntry->Unknown4 = 0;
           RsdsEntry->Unknown5 = 0;
+        } else if (RsdsEntry->Signature == CODEVIEW_SIGNATURE_MTOC) {
+          // MTOC sets DebugDirectoryEntrySize to size of the .debug section, so fix it.
+          if (!ZeroDebugFlag) {
+            if (Optional32Hdr->Magic == EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
+              Optional32Hdr->DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG].Size = sizeof (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY);
+            } else {
+              Optional64Hdr->DataDirectory[EFI_IMAGE_DIRECTORY_ENTRY_DEBUG].Size = sizeof (EFI_IMAGE_DEBUG_DIRECTORY_ENTRY);
+            }
+          }
+          break;
         }
       }
     }