diff --git a/ChangeLog b/ChangeLog
index 90654ab47..1fed051d3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -29,9 +29,10 @@ API Changes
      changed from ssl_context to ssl_config.
    * mbedtls_ssl_conf_ca_chain() lost its last argument (peer_cn), now set
      using mbedtls_ssl_set_hostname().
-   * mbedtls_ssl_set_session_cached() changed prototype (only one context
+   * mbedtls_ssl_conf_session_cache() changed prototype (only one context
      pointer, parameters reordered).
-   * mbedtls_memory_bufer_alloc_init() now returns void
+   * mbedtls_ssl_conf_truncated_hmac() now returns void.
+   * mbedtls_memory_bufer_alloc_init() now returns void.
    * In the threading layer, mbedtls_mutex_init() and mbedtls_mutex_free() now
      return void.
    * ecdsa_write_signature() gained an addtional md_alg argument and
@@ -96,9 +97,13 @@ Reauirement changes
    * The NET layer now unconditionnaly relies on getaddrinfo().
    * Compiler is required to support C99 types such as long long and uint32_t.
 
-Changes from the 1.4 preview branch
+API changes from the 1.4 preview branch
    * ssl_set_bio_timeout() was removed, split into mbedtls_ssl_set_bio() with
      new prototype, and mbedtls_ssl_set_read_timeout().
+   * The following functions now return void:
+     mbedtls_ssl_conf_transport()
+     mbedtls_ssl_conf_max_version()
+     mbedtls_ssl_conf_min_version()
 
 Changes
    * mbedtls_ctr_drbg_random() and mbedtls_hmac_drbg_random() are now
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 742e9e440..b5e6a8c8d 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1185,17 +1185,16 @@ void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint );
  * \brief           Set the transport type (TLS or DTLS).
  *                  Default: TLS
  *
+ * \note            For DTLS, you must either provide a recv callback that
+ *                  doesn't block, or one that handles timeouts, see
+ *                  mbedtls_ssl_conf_bio()
+ *
  * \param conf      SSL configuration
  * \param transport transport type:
  *                  MBEDTLS_SSL_TRANSPORT_STREAM for TLS,
  *                  MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS.
- * \return          0 on success or MBEDTLS_ERR_SSL_BAD_INPUT_DATA
- *
- * \note            For DTLS, you must either provide a recv callback that
- *                  doesn't block, or one that handles timeouts, see
- *                  mbedtls_ssl_conf_bio()
  */
-int mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport );
+void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport );
 
 /**
  * \brief          Set the certificate verification mode
@@ -1799,19 +1798,18 @@ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl );
  *                 and/or accepted at the server side
  *                 (Default: MBEDTLS_SSL_MAX_MAJOR_VERSION, MBEDTLS_SSL_MAX_MINOR_VERSION)
  *
- *                 Note: This ignores ciphersuites from 'higher' versions.
+ * \note           This ignores ciphersuites from higher versions.
+ *
+ * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
+ *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
  *
  * \param conf     SSL configuration
  * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
  * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
  *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
  *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
- * \return         0 on success or MBEDTLS_ERR_SSL_BAD_INPUT_DATA
- *
- * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
- *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
  */
-int mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor );
+void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor );
 
 /**
  * \brief          Set the minimum accepted SSL/TLS protocol version
@@ -1822,17 +1820,16 @@ int mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor
  *
  * \note           MBEDTLS_SSL_MINOR_VERSION_0 (SSL v3) should be avoided.
  *
+ * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
+ *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
+ *
  * \param conf     SSL configuration
  * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
  * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
  *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
  *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
- * \return         0 on success or MBEDTLS_ERR_SSL_BAD_INPUT_DATA
- *
- * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
- *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
  */
-int mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor );
+void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor );
 
 #if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C)
 /**
@@ -1929,10 +1926,8 @@ int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_c
  * \param conf     SSL configuration
  * \param truncate Enable or disable (MBEDTLS_SSL_TRUNC_HMAC_ENABLED or
  *                                    MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
- *
- * \return         Always 0.
  */
-int mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate );
+void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate );
 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
 
 #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index b098e0dd3..8263573b6 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5185,11 +5185,9 @@ void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint )
     conf->endpoint   = endpoint;
 }
 
-int mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport )
+void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport )
 {
     conf->transport = transport;
-
-    return( 0 );
 }
 
 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
@@ -5564,50 +5562,16 @@ const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl )
 }
 #endif /* MBEDTLS_SSL_ALPN */
 
-static int ssl_check_version( const mbedtls_ssl_config *conf,
-                              int major, int minor )
+void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor )
 {
-    if( major < MBEDTLS_SSL_MIN_MAJOR_VERSION ||
-        major > MBEDTLS_SSL_MAX_MAJOR_VERSION ||
-        minor < MBEDTLS_SSL_MIN_MINOR_VERSION ||
-        minor > MBEDTLS_SSL_MAX_MINOR_VERSION )
-    {
-        return( -1 );
-    }
-
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-    if( conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
-        minor < MBEDTLS_SSL_MINOR_VERSION_2 )
-    {
-        return( -1 );
-    }
-#else
-    ((void) ssl);
-#endif
-
-    return( 0 );
-}
-
-int mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor )
-{
-    if( ssl_check_version( conf, major, minor ) != 0 )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
     conf->max_major_ver = major;
     conf->max_minor_ver = minor;
-
-    return( 0 );
 }
 
-int mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor )
+void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor )
 {
-    if( ssl_check_version( conf, major, minor ) != 0 )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
     conf->min_major_ver = major;
     conf->min_minor_ver = minor;
-
-    return( 0 );
 }
 
 #if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C)
@@ -5652,11 +5616,9 @@ int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_c
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
-int mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate )
+void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate )
 {
     conf->trunc_hmac = truncate;
-
-    return( 0 );
 }
 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
 
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 6620d4eab..8d04b9af3 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1183,24 +1183,10 @@ int main( int argc, char *argv[] )
 #endif
 
     if( opt.min_version != DFL_MIN_VERSION )
-    {
-        ret = mbedtls_ssl_conf_min_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.min_version );
-        if( ret != 0 )
-        {
-            mbedtls_printf( " failed\n  ! selected min_version is not available\n" );
-            goto exit;
-        }
-    }
+        mbedtls_ssl_conf_min_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.min_version );
 
     if( opt.max_version != DFL_MAX_VERSION )
-    {
-        ret = mbedtls_ssl_conf_max_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.max_version );
-        if( ret != 0 )
-        {
-            mbedtls_printf( " failed\n  ! selected max_version is not available\n" );
-            goto exit;
-        }
-    }
+        mbedtls_ssl_conf_max_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.max_version );
 
 #if defined(MBEDTLS_SSL_FALLBACK_SCSV)
     if( opt.fallback != DFL_FALLBACK )
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 81b92a6d4..b9e2c09e7 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -1735,24 +1735,10 @@ int main( int argc, char *argv[] )
 #endif
 
     if( opt.min_version != DFL_MIN_VERSION )
-    {
-        ret = mbedtls_ssl_conf_min_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.min_version );
-        if( ret != 0 )
-        {
-            mbedtls_printf( " failed\n  ! selected min_version is not available\n" );
-            goto exit;
-        }
-    }
+        mbedtls_ssl_conf_min_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.min_version );
 
     if( opt.max_version != DFL_MIN_VERSION )
-    {
-        ret = mbedtls_ssl_conf_max_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.max_version );
-        if( ret != 0 )
-        {
-            mbedtls_printf( " failed\n  ! selected max_version is not available\n" );
-            goto exit;
-        }
-    }
+        mbedtls_ssl_conf_max_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.max_version );
 
     mbedtls_printf( " ok\n" );