diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 1cfda4a..95d6468 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4550,44 +4550,62 @@
  * Serialize a session in the following format:
  * (in the presentation language of TLS, RFC 8446 section 3)
  *
- *  opaque mbedtls_version[3];   // major, minor, patch
- *  opaque session_format[2];    // version-specific 16-bit field determining
- *                               // the format of the remaining
- *                               // serialized data.
+ *  struct {
  *
- *  Note: When updating the format, remember to keep
- *        these version+format bytes.
+ *    opaque mbedtls_version[3];   // major, minor, patch
+ *    opaque session_format[2];    // version-specific 16-bit field determining
+ *                                 // the format of the remaining
+ *                                 // serialized data.
  *
- *                               // In this version, `session_format` determines
- *                               // the setting of those compile-time
- *                               // configuration options which influence
- *                               // the structure of mbedtls_ssl_session.
- *  uint64 start_time;
- *  uint8 ciphersuite[2];        // defined by the standard
- *  uint8 compression;           // 0 or 1
- *  uint8 session_id_len;        // at most 32
- *  opaque session_id[32];
- *  opaque master[48];           // fixed length in the standard
- *  uint32 verify_result;
- *  opaque peer_cert<0..2^24-1>; // length 0 means no peer cert
- *  opaque ticket<0..2^24-1>;    // length 0 means no ticket
- *  uint32 ticket_lifetime;
- *  uint8 mfl_code;              // up to 255 according to standard
- *  uint8 trunc_hmac;            // 0 or 1
- *  uint8 encrypt_then_mac;      // 0 or 1
+ *          Note: When updating the format, remember to keep
+ *          these version+format bytes.
  *
- * The order is the same as in the definition of the structure, except
- * verify_result is put before peer_cert so that all mandatory fields come
- * together in one block.
+ *                                 // In this version, `session_format` determines
+ *                                 // the setting of those compile-time
+ *                                 // configuration options which influence
+ *                                 // the structure of mbedtls_ssl_session.
+ *
+ *    uint8_t minor_ver;           // Possible values:
+ *                                 // - TLS 1.2 (MBEDTLS_SSL_MINOR_VERSION_3)
+ *
+ *    select (serialized_session.minor_ver) {
+ *
+ *      case MBEDTLS_SSL_MINOR_VERSION_3: // TLS 1.2
+ *        serialized_session_tls12 data;
+ *
+ *   };
+ *
+ * } serialized_session;
+ *
  */
-static int ssl_session_save( const mbedtls_ssl_session *session,
-                             unsigned char omit_header,
-                             unsigned char *buf,
-                             size_t buf_len,
-                             size_t *olen )
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+/* Serialization of TLS 1.2 sessions:
+ *
+ * struct {
+ *    uint64 start_time;
+ *    uint8 ciphersuite[2];           // defined by the standard
+ *    uint8 compression;              // 0 or 1
+ *    uint8 session_id_len;           // at most 32
+ *    opaque session_id[32];
+ *    opaque master[48];              // fixed length in the standard
+ *    uint32 verify_result;
+ *    opaque peer_cert<0..2^24-1>;    // length 0 means no peer cert
+ *    opaque ticket<0..2^24-1>;       // length 0 means no ticket
+ *    uint32 ticket_lifetime;
+ *    uint8 mfl_code;                 // up to 255 according to standard
+ *    uint8 trunc_hmac;               // 0 or 1
+ *    uint8 encrypt_then_mac;         // 0 or 1
+ * } serialized_session_tls12;
+ *
+ */
+static size_t ssl_session_save_tls12( const mbedtls_ssl_session *session,
+                                      unsigned char *buf,
+                                      size_t buf_len )
 {
     unsigned char *p = buf;
     size_t used = 0;
+
 #if defined(MBEDTLS_HAVE_TIME)
     uint64_t start;
 #endif
@@ -4597,23 +4615,6 @@
 #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
-
-    if( !omit_header )
-    {
-        /*
-         * Add version identifier
-         */
-
-        used += sizeof( ssl_serialized_session_header );
-
-        if( used <= buf_len )
-        {
-            memcpy( p, ssl_serialized_session_header,
-                    sizeof( ssl_serialized_session_header ) );
-            p += sizeof( ssl_serialized_session_header );
-        }
-    }
-
     /*
      * Time
      */
@@ -4756,9 +4757,61 @@
         *p++ = (unsigned char)( ( session->encrypt_then_mac ) & 0xFF );
 #endif
 
-    /* Done */
-    *olen = used;
+    return( used );
+}
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
+static int ssl_session_save( const mbedtls_ssl_session *session,
+                             unsigned char omit_header,
+                             unsigned char *buf,
+                             size_t buf_len,
+                             size_t *olen )
+{
+    unsigned char *p = buf;
+    size_t used = 0;
+
+    if( !omit_header )
+    {
+        /*
+         * Add Mbed TLS version identifier
+         */
+
+        used += sizeof( ssl_serialized_session_header );
+
+        if( used <= buf_len )
+        {
+            memcpy( p, ssl_serialized_session_header,
+                    sizeof( ssl_serialized_session_header ) );
+            p += sizeof( ssl_serialized_session_header );
+        }
+    }
+
+    /*
+     * TLS version identifier
+     */
+    used += 1;
+    if( used <= buf_len )
+    {
+        *p++ = session->minor_ver;
+    }
+
+    /* Forward to version-specific serialization routine. */
+    switch( session->minor_ver )
+    {
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+    case MBEDTLS_SSL_MINOR_VERSION_3:
+    {
+        size_t remaining_len = used <= buf_len ? buf_len - used : 0;
+        used += ssl_session_save_tls12( session, p, remaining_len );
+        break;
+    }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+
+    default:
+        return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+    }
+
+    *olen = used;
     if( used > buf_len )
         return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
 
@@ -4782,13 +4835,10 @@
  * This internal version is wrapped by a public function that cleans up in
  * case of error, and has an extra option omit_header.
  */
-static int ssl_session_load( mbedtls_ssl_session *session,
-                             unsigned char omit_header,
-                             const unsigned char *buf,
-                             size_t len )
+static int ssl_session_load_tls12( mbedtls_ssl_session *session,
+                                   const unsigned char *buf,
+                                   size_t len )
 {
-    const unsigned char *p = buf;
-    const unsigned char * const end = buf + len;
 #if defined(MBEDTLS_HAVE_TIME)
     uint64_t start;
 #endif
@@ -4798,22 +4848,8 @@
 #endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
-    if( !omit_header )
-    {
-        /*
-         * Check version identifier
-         */
-
-        if( (size_t)( end - p ) < sizeof( ssl_serialized_session_header ) )
-            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
-        if( memcmp( p, ssl_serialized_session_header,
-                    sizeof( ssl_serialized_session_header ) ) != 0 )
-        {
-            return( MBEDTLS_ERR_SSL_VERSION_MISMATCH );
-        }
-        p += sizeof( ssl_serialized_session_header );
-    }
+    const unsigned char *p = buf;
+    const unsigned char * const end = buf + len;
 
     /*
      * Time
@@ -4998,6 +5034,54 @@
     return( 0 );
 }
 
+static int ssl_session_load( mbedtls_ssl_session *session,
+                             unsigned char omit_header,
+                             const unsigned char *buf,
+                             size_t len )
+{
+    const unsigned char *p = buf;
+    const unsigned char * const end = buf + len;
+
+    if( !omit_header )
+    {
+        /*
+         * Check Mbed TLS version identifier
+         */
+
+        if( (size_t)( end - p ) < sizeof( ssl_serialized_session_header ) )
+            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+        if( memcmp( p, ssl_serialized_session_header,
+                    sizeof( ssl_serialized_session_header ) ) != 0 )
+        {
+            return( MBEDTLS_ERR_SSL_VERSION_MISMATCH );
+        }
+        p += sizeof( ssl_serialized_session_header );
+    }
+
+    /*
+     * TLS version identifier
+     */
+    if( 1 > (size_t)( end - p ) )
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+    session->minor_ver = *p++;
+
+    /* Dispatch according to TLS version. */
+    switch( session->minor_ver )
+    {
+#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
+    case MBEDTLS_SSL_MINOR_VERSION_3: /* TLS 1.2 */
+    {
+        size_t remaining_len = ( end - p );
+        return( ssl_session_load_tls12( session, p, remaining_len ) );
+    }
+#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
+
+    default:
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+    }
+}
+
 /*
  * Deserialize session: public wrapper for error cleaning
  */