diff --git a/tests/suites/test_suite_ecdsa.function b/tests/suites/test_suite_ecdsa.function
index 22d92b6..fa77dfa 100644
--- a/tests/suites/test_suite_ecdsa.function
+++ b/tests/suites/test_suite_ecdsa.function
@@ -307,7 +307,7 @@
     mbedtls_mpi d, r, s, r_check, s_check;
     unsigned char hash[MBEDTLS_MD_MAX_SIZE];
     size_t hlen;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
 
     mbedtls_ecp_group_init( &grp );
     mbedtls_mpi_init( &d ); mbedtls_mpi_init( &r ); mbedtls_mpi_init( &s );
@@ -320,7 +320,7 @@
     TEST_ASSERT( mbedtls_mpi_read_string( &s_check, 16, s_str ) == 0 );
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     hlen = mbedtls_md_get_size( md_info );
     TEST_ASSERT( mbedtls_md( md_info, (const unsigned char *) msg,
                  strlen( msg ), hash ) == 0 );
@@ -476,7 +476,7 @@
     unsigned char sig[MBEDTLS_ECDSA_MAX_LEN];
     unsigned char sig_check[MBEDTLS_ECDSA_MAX_LEN];
     size_t hlen, slen, slen_check;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
 
     mbedtls_ecdsa_restart_init( &rs_ctx );
     mbedtls_ecdsa_init( &ctx );
@@ -489,7 +489,7 @@
     slen_check = unhexify( sig_check, sig_str );
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     hlen = mbedtls_md_get_size( md_info );
     mbedtls_md( md_info, (const unsigned char *) msg, strlen( msg ), hash );
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
index 3e87207..7e83b57 100644
--- a/tests/suites/test_suite_hkdf.function
+++ b/tests/suites/test_suite_hkdf.function
@@ -25,8 +25,8 @@
      */
     unsigned char okm_hex[257] = { '\0' };
 
-    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md != NULL );
+    mbedtls_md_handle_t md = mbedtls_md_info_from_type( md_alg );
+    TEST_ASSERT( md != MBEDTLS_MD_INVALID_HANDLE );
 
     ikm_len = unhexify( ikm, hex_ikm_string );
     salt_len = unhexify( salt, hex_salt_string );
@@ -54,8 +54,8 @@
     unsigned char *output_prk = NULL;
     size_t ikm_len, salt_len, prk_len, output_prk_len;
 
-    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md != NULL );
+    mbedtls_md_handle_t md = mbedtls_md_info_from_type( md_alg );
+    TEST_ASSERT( md != MBEDTLS_MD_INVALID_HANDLE );
 
     output_prk_len = mbedtls_md_get_size( md );
     output_prk = mbedtls_calloc( 1, output_prk_len );
@@ -90,8 +90,8 @@
     unsigned char *output_okm = NULL;
     size_t info_len, prk_len, okm_len;
 
-    const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md != NULL );
+    mbedtls_md_handle_t md = mbedtls_md_info_from_type( md_alg );
+    TEST_ASSERT( md != MBEDTLS_MD_INVALID_HANDLE );
 
     output_okm = mbedtls_calloc( OKM_LEN, 1 );
 
diff --git a/tests/suites/test_suite_hmac_drbg.function b/tests/suites/test_suite_hmac_drbg.function
index 13bc400..da280db 100644
--- a/tests/suites/test_suite_hmac_drbg.function
+++ b/tests/suites/test_suite_hmac_drbg.function
@@ -34,7 +34,7 @@
 {
     unsigned char out[16];
     unsigned char buf[1024];
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
     entropy_ctx entropy;
     size_t last_len, i, reps = 10;
@@ -47,7 +47,7 @@
     entropy.p = buf;
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     /* Init must use entropy */
     last_len = entropy.len;
@@ -112,13 +112,13 @@
 /* BEGIN_CASE depends_on:MBEDTLS_FS_IO */
 void hmac_drbg_seed_file( int md_alg, char * path, int ret )
 {
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
 
     mbedtls_hmac_drbg_init( &ctx );
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT( mbedtls_hmac_drbg_seed( &ctx, md_info, rnd_std_rand, NULL,
                                  NULL, 0 ) == 0 );
@@ -136,7 +136,7 @@
 {
     unsigned char out[16];
     unsigned char buf[100];
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
     size_t i;
 
@@ -145,7 +145,7 @@
     memset( out, 0, sizeof( out ) );
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT( mbedtls_hmac_drbg_seed_buf( &ctx, md_info, buf, sizeof( buf ) ) == 0 );
 
     /* Make sure it never tries to reseed (would segfault otherwise) */
@@ -168,7 +168,7 @@
     unsigned char data[1024];
     unsigned char my_output[512];
     entropy_ctx p_entropy;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
 
     mbedtls_hmac_drbg_init( &ctx );
@@ -177,7 +177,7 @@
     p_entropy.len = entropy->len;
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     /* Test the simplified buffer-based variant */
     memcpy( data, entropy->x, p_entropy.len );
@@ -215,7 +215,7 @@
 {
     unsigned char my_output[512];
     entropy_ctx p_entropy;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
 
     mbedtls_hmac_drbg_init( &ctx );
@@ -224,7 +224,7 @@
     p_entropy.len = entropy->len;
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT( mbedtls_hmac_drbg_seed( &ctx, md_info, mbedtls_test_entropy_func, &p_entropy,
                                  custom->x, custom->len ) == 0 );
@@ -247,7 +247,7 @@
 {
     unsigned char my_output[512];
     entropy_ctx p_entropy;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     mbedtls_hmac_drbg_context ctx;
 
     mbedtls_hmac_drbg_init( &ctx );
@@ -256,7 +256,7 @@
     p_entropy.len = entropy->len;
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT( mbedtls_hmac_drbg_seed( &ctx, md_info, mbedtls_test_entropy_func, &p_entropy,
                                  custom->x, custom->len ) == 0 );
diff --git a/tests/suites/test_suite_md.function b/tests/suites/test_suite_md.function
index 11cf88a..515a28c 100644
--- a/tests/suites/test_suite_md.function
+++ b/tests/suites/test_suite_md.function
@@ -11,7 +11,7 @@
 void mbedtls_md_process(  )
 {
     const int *md_type_ptr;
-    const mbedtls_md_info_t *info;
+    mbedtls_md_handle_t info;
     mbedtls_md_context_t ctx;
     unsigned char buf[150];
 
@@ -28,7 +28,7 @@
     for( md_type_ptr = mbedtls_md_list(); *md_type_ptr != 0; md_type_ptr++ )
     {
         info = mbedtls_md_info_from_type( *md_type_ptr );
-        TEST_ASSERT( info != NULL );
+        TEST_ASSERT( info != MBEDTLS_MD_INVALID_HANDLE );
         TEST_ASSERT( mbedtls_md_setup( &ctx, info, 0 ) == 0 );
         TEST_ASSERT( mbedtls_md_process( &ctx, buf ) == 0 );
         mbedtls_md_free( &ctx );
@@ -43,18 +43,22 @@
 void md_null_args(  )
 {
     mbedtls_md_context_t ctx;
-    const mbedtls_md_info_t *info = mbedtls_md_info_from_type( *( mbedtls_md_list() ) );
+    mbedtls_md_handle_t info = mbedtls_md_info_from_type( *( mbedtls_md_list() ) );
     unsigned char buf[1] = { 0 };
 
     mbedtls_md_init( &ctx );
 
-    TEST_ASSERT( mbedtls_md_get_size( NULL ) == 0 );
-    TEST_ASSERT( mbedtls_md_get_type( NULL ) == MBEDTLS_MD_NONE );
-    TEST_ASSERT( mbedtls_md_get_name( NULL ) == NULL );
+    TEST_ASSERT( mbedtls_md_get_size( MBEDTLS_MD_INVALID_HANDLE )
+                 == 0 );
+    TEST_ASSERT( mbedtls_md_get_type( MBEDTLS_MD_INVALID_HANDLE )
+                 == MBEDTLS_MD_NONE );
+    TEST_ASSERT( mbedtls_md_get_name( MBEDTLS_MD_INVALID_HANDLE )
+                 == NULL );
 
-    TEST_ASSERT( mbedtls_md_info_from_string( NULL ) == NULL );
+    TEST_ASSERT( mbedtls_md_info_from_string( NULL ) == MBEDTLS_MD_INVALID_HANDLE );
 
-    TEST_ASSERT( mbedtls_md_setup( &ctx, NULL, 0 ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
+    TEST_ASSERT( mbedtls_md_setup( &ctx, MBEDTLS_MD_INVALID_HANDLE, 0 )
+                 == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_md_setup( NULL, info, 0 ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
     TEST_ASSERT( mbedtls_md_starts( NULL ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
@@ -66,10 +70,12 @@
     TEST_ASSERT( mbedtls_md_finish( NULL, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_md_finish( &ctx, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
-    TEST_ASSERT( mbedtls_md( NULL, buf, 1, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
+    TEST_ASSERT( mbedtls_md( MBEDTLS_MD_INVALID_HANDLE,
+                             buf, 1, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
 #if defined(MBEDTLS_FS_IO)
-    TEST_ASSERT( mbedtls_md_file( NULL, "", buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
+    TEST_ASSERT( mbedtls_md_file( MBEDTLS_MD_INVALID_HANDLE,
+                                  "", buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 #endif
 
     TEST_ASSERT( mbedtls_md_hmac_starts( NULL, buf, 1 )
@@ -90,27 +96,29 @@
     TEST_ASSERT( mbedtls_md_hmac_reset( NULL ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_md_hmac_reset( &ctx ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
-    TEST_ASSERT( mbedtls_md_hmac( NULL, buf, 1, buf, 1, buf )
+    TEST_ASSERT( mbedtls_md_hmac( MBEDTLS_MD_INVALID_HANDLE, buf, 1, buf, 1, buf )
                  == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
     TEST_ASSERT( mbedtls_md_process( NULL, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_md_process( &ctx, buf ) == MBEDTLS_ERR_MD_BAD_INPUT_DATA );
 
     /* Ok, this is not NULL arg but NULL return... */
-    TEST_ASSERT( mbedtls_md_info_from_type( MBEDTLS_MD_NONE ) == NULL );
-    TEST_ASSERT( mbedtls_md_info_from_string( "no such md" ) == NULL );
+    TEST_ASSERT( mbedtls_md_info_from_type( MBEDTLS_MD_NONE ) ==
+                 MBEDTLS_MD_INVALID_HANDLE );
+    TEST_ASSERT( mbedtls_md_info_from_string( "no such md" ) ==
+                 MBEDTLS_MD_INVALID_HANDLE );
 }
 /* END_CASE */
 
 /* BEGIN_CASE */
 void md_info( int md_type, char * md_name, int md_size )
 {
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
     const int *md_type_ptr;
     int found;
 
     md_info = mbedtls_md_info_from_type( md_type );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT( md_info == mbedtls_md_info_from_string( md_name ) );
 
     TEST_ASSERT( mbedtls_md_get_type( md_info ) == (mbedtls_md_type_t) md_type );
@@ -132,7 +140,7 @@
     char md_name[100];
     unsigned char src_str[1000];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
 
     memset( md_name, 0x00, 100 );
     memset( src_str, 0x00, 1000 );
@@ -141,7 +149,7 @@
     strncpy( (char *) src_str, text_src_string, sizeof( src_str ) - 1 );
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string(md_name);
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT ( 0 == mbedtls_md( md_info, src_str, strlen( (char *) src_str ), output ) );
 
@@ -155,14 +163,14 @@
 {
     char md_name[100];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
 
     memset( md_name, 0x00, 100 );
     memset( output, 0x00, 100 );
 
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string( md_name );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT ( 0 == mbedtls_md( md_info, src_str->x, src_str->len, output ) );
 
@@ -181,7 +189,7 @@
     unsigned char output[100];
     int halfway, len;
 
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
     mbedtls_md_context_t ctx, ctx_copy;
 
     mbedtls_md_init( &ctx );
@@ -197,7 +205,7 @@
     halfway = len / 2;
 
     md_info = mbedtls_md_info_from_string(md_name);
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT ( 0 == mbedtls_md_setup( &ctx, md_info, 0 ) );
     TEST_ASSERT ( 0 == mbedtls_md_setup( &ctx_copy, md_info, 0 ) );
 
@@ -230,7 +238,7 @@
 {
     char md_name[100];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
     mbedtls_md_context_t ctx, ctx_copy;
     int halfway;
 
@@ -242,7 +250,7 @@
 
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string(md_name);
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT ( 0 == mbedtls_md_setup( &ctx, md_info, 0 ) );
     TEST_ASSERT ( 0 == mbedtls_md_setup( &ctx_copy, md_info, 0 ) );
 
@@ -277,14 +285,14 @@
 {
     char md_name[100];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
 
     memset( md_name, 0x00, 100 );
     memset( output, 0x00, 100 );
 
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string( md_name );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
 
     TEST_ASSERT ( mbedtls_md_hmac( md_info, key_str->x, key_str->len, src_str->x, src_str->len, output ) == 0 );
@@ -299,7 +307,7 @@
 {
     char md_name[100];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
     mbedtls_md_context_t ctx;
     int halfway;
 
@@ -310,7 +318,7 @@
 
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string( md_name );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT ( 0 == mbedtls_md_setup( &ctx, md_info, 1 ) );
 
     halfway = src_str->len / 2;
@@ -344,14 +352,14 @@
 {
     char md_name[100];
     unsigned char output[100];
-    const mbedtls_md_info_t *md_info = NULL;
+    mbedtls_md_handle_t md_info = MBEDTLS_MD_INVALID_HANDLE;
 
     memset( md_name, 0x00, 100 );
     memset( output, 0x00, 100 );
 
     strncpy( (char *) md_name, text_md_name, sizeof( md_name ) - 1 );
     md_info = mbedtls_md_info_from_string( md_name );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     TEST_ASSERT( mbedtls_md_file( md_info, filename, output ) == 0 );
 
diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 8b95bab..fc917d0 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -593,7 +593,7 @@
     TEST_ASSERT( mbedtls_mpi_read_string( &rsa->E, radix_E, input_E ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
 
     TEST_ASSERT( mbedtls_pk_verify( &pk, digest, hash_result, 0,
@@ -709,7 +709,7 @@
     unsigned char sig[MBEDTLS_ECDSA_MAX_LEN];
     unsigned char sig_check[MBEDTLS_ECDSA_MAX_LEN];
     size_t hlen, slen, slen_check;
-    const mbedtls_md_info_t *md_info;
+    mbedtls_md_handle_t md_info;
 
     mbedtls_pk_restart_init( &rs_ctx );
     mbedtls_pk_init( &prv );
@@ -729,7 +729,7 @@
     slen_check = unhexify( sig_check, sig_str );
 
     md_info = mbedtls_md_info_from_type( md_alg );
-    TEST_ASSERT( md_info != NULL );
+    TEST_ASSERT( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
     hlen = mbedtls_md_get_size( md_info );
     mbedtls_md( md_info, (const unsigned char *) msg, strlen( msg ), hash );
diff --git a/tests/suites/test_suite_pkcs1_v15.function b/tests/suites/test_suite_pkcs1_v15.function
index 0723623..58c25bf 100644
--- a/tests/suites/test_suite_pkcs1_v15.function
+++ b/tests/suites/test_suite_pkcs1_v15.function
@@ -275,8 +275,10 @@
     TEST_ASSERT( mbedtls_rsa_check_privkey( &ctx ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_sign( &ctx, &rnd_buffer_rand, &info, MBEDTLS_RSA_PRIVATE, digest, 0, hash_result, output ) == result );
     if( result == 0 )
@@ -313,9 +315,10 @@
     TEST_ASSERT( mbedtls_rsa_get_len( &ctx ) == (size_t) ( ( mod + 7 ) / 8 ) );
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
 
-
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_verify( &ctx, NULL, NULL, MBEDTLS_RSA_PUBLIC, digest, 0, hash_result, result_str->x ) == result );
 
diff --git a/tests/suites/test_suite_pkcs1_v21.function b/tests/suites/test_suite_pkcs1_v21.function
index 99be08a..a9635e1 100644
--- a/tests/suites/test_suite_pkcs1_v21.function
+++ b/tests/suites/test_suite_pkcs1_v21.function
@@ -128,8 +128,10 @@
     TEST_ASSERT( mbedtls_rsa_check_privkey( &ctx ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_sign( &ctx, &rnd_buffer_rand, &info, MBEDTLS_RSA_PRIVATE,
                                          digest, 0, hash_result, output ) == result );
@@ -169,8 +171,10 @@
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_verify( &ctx, NULL, NULL, MBEDTLS_RSA_PUBLIC, digest, 0, hash_result, result_str->x ) == result );
 
diff --git a/tests/suites/test_suite_pkcs5.function b/tests/suites/test_suite_pkcs5.function
index 26f1d33..a8f0523 100644
--- a/tests/suites/test_suite_pkcs5.function
+++ b/tests/suites/test_suite_pkcs5.function
@@ -12,14 +12,14 @@
                   int it_cnt, int key_len, data_t * result_key_string )
 {
     mbedtls_md_context_t ctx;
-    const mbedtls_md_info_t *info;
+    mbedtls_md_handle_t info;
 
     unsigned char key[100];
 
     mbedtls_md_init( &ctx );
 
     info = mbedtls_md_info_from_type( hash );
-    TEST_ASSERT( info != NULL );
+    TEST_ASSERT( info != MBEDTLS_MD_INVALID_HANDLE );
     TEST_ASSERT( mbedtls_md_setup( &ctx, info, 1 ) == 0 );
     TEST_ASSERT( mbedtls_pkcs5_pbkdf2_hmac( &ctx, pw_str->x, pw_str->len, salt_str->x, salt_str->len,
                                      it_cnt, key_len, key ) == 0 );
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index f2a9b98..4d22c9b 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -497,8 +497,10 @@
     TEST_ASSERT( mbedtls_rsa_check_privkey( &ctx ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_sign( &ctx, &rnd_pseudo_rand, &rnd_info,
                                          MBEDTLS_RSA_PRIVATE, digest, 0,
@@ -538,8 +540,10 @@
     TEST_ASSERT( mbedtls_rsa_check_pubkey( &ctx ) == 0 );
 
 
-    if( mbedtls_md_info_from_type( digest ) != NULL )
+    if( mbedtls_md_info_from_type( digest ) != MBEDTLS_MD_INVALID_HANDLE )
+    {
         TEST_ASSERT( mbedtls_md( mbedtls_md_info_from_type( digest ), message_str->x, message_str->len, hash_result ) == 0 );
+    }
 
     TEST_ASSERT( mbedtls_rsa_pkcs1_verify( &ctx, NULL, NULL, MBEDTLS_RSA_PUBLIC, digest, 0, hash_result, result_str->x ) == result );
 
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index b177779..80f5f16 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -102,12 +102,12 @@
     if( cipher_info->mode == MBEDTLS_MODE_CBC ||
         cipher_info->mode == MBEDTLS_MODE_STREAM )
     {
-        mbedtls_md_info_t const *md_info;
+        mbedtls_md_handle_t md_info;
         unsigned char *md0, *md1;
 
         /* Pick hash */
         md_info = mbedtls_md_info_from_type( hash_id );
-        CHK( md_info != NULL );
+        CHK( md_info != MBEDTLS_MD_INVALID_HANDLE );
 
         /* Pick hash keys */
         maclen = mbedtls_md_get_size( md_info );