diff --git a/MdePkg/Include/Protocol/Tls.h b/MdePkg/Include/Protocol/Tls.h
index 2119f33c0f..dafaabcd2a 100644
--- a/MdePkg/Include/Protocol/Tls.h
+++ b/MdePkg/Include/Protocol/Tls.h
@@ -141,10 +141,12 @@ typedef enum {
 ///       Hello Messages". The value of EFI_TLS_CIPHER is from TLS Cipher
 ///       Suite Registry of IANA.
 ///
+#pragma pack (1)
 typedef struct {
   UINT8                         Data1;
   UINT8                         Data2;
 } EFI_TLS_CIPHER;
+#pragma pack ()
 
 ///
 /// EFI_TLS_COMPRESSION
@@ -157,11 +159,13 @@ typedef UINT8 EFI_TLS_COMPRESSION;
 /// Note: The definition of EFI_TLS_EXTENSION if from "RFC 5246 A.4.1.
 ///       Hello Messages".
 ///
+#pragma pack (1)
 typedef struct {
   UINT16                        ExtensionType;
   UINT16                        Length;
   UINT8                         Data[1];
 } EFI_TLS_EXTENSION;
+#pragma pack ()
 
 ///
 /// EFI_TLS_VERIFY
@@ -194,29 +198,35 @@ typedef UINT32  EFI_TLS_VERIFY;
 /// Note: The definition of EFI_TLS_RANDOM is from "RFC 5246 A.4.1.
 ///       Hello Messages".
 ///
+#pragma pack (1)
 typedef struct {
   UINT32                        GmtUnixTime;
   UINT8                         RandomBytes[28];
 } EFI_TLS_RANDOM;
+#pragma pack ()
 
 ///
 /// EFI_TLS_MASTER_SECRET
 /// Note: The definition of EFI_TLS_MASTER_SECRET is from "RFC 5246 8.1.
 ///       Computing the Master Secret".
 ///
+#pragma pack (1)
 typedef struct {
   UINT8                         Data[48];
 } EFI_TLS_MASTER_SECRET;
+#pragma pack ()
 
 ///
 /// EFI_TLS_SESSION_ID
 /// Note: The definition of EFI_TLS_SESSION_ID is from "RFC 5246 A.4.1. Hello Messages".
 ///
 #define MAX_TLS_SESSION_ID_LENGTH  32
+#pragma pack (1)
 typedef struct {
   UINT16                        Length;
   UINT8                         Data[MAX_TLS_SESSION_ID_LENGTH];
 } EFI_TLS_SESSION_ID;
+#pragma pack ()
 
 ///
 /// EFI_TLS_SESSION_STATE