diff --git a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
index e7d4ae3e55..3fa985f567 100644
--- a/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
+++ b/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c
@@ -451,7 +451,7 @@ PciIoMemRead (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }  
@@ -526,7 +526,7 @@ PciIoMemWrite (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }
@@ -600,7 +600,7 @@ PciIoIoRead (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }    
@@ -674,7 +674,7 @@ PciIoIoWrite (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }  
@@ -739,7 +739,7 @@ PciIoConfigRead (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }    
@@ -804,7 +804,7 @@ PciIoConfigWrite (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((Offset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }  
@@ -899,7 +899,7 @@ PciIoCopyMem (
   //  
   if (FeaturePcdGet (PcdUnalignedPciIoEnable)) {
     if ((SrcOffset & ((1 << (Width & 0x03)) - 1)) != 0 || (DestOffset & ((1 << (Width & 0x03)) - 1)) != 0) {
-      Width &= (~0x03);
+      Width = (EFI_PCI_IO_PROTOCOL_WIDTH) (Width & (~0x03));
       Count *=  (UINTN)(1 << (Width & 0x03));
     }
   }