diff --git a/include/mbedtls/ecdh.h b/include/mbedtls/ecdh.h
index 2a0980b39..587035aad 100644
--- a/include/mbedtls/ecdh.h
+++ b/include/mbedtls/ecdh.h
@@ -222,10 +222,7 @@ int mbedtls_ecdh_gen_public( mbedtls_ecp_group *grp, mbedtls_mpi *d, mbedtls_ecp
  *                  This must be initialized.
  * \param d         Our secret exponent (private key).
  *                  This must be initialized.
- * \param f_rng     The RNG function. This may be \c NULL if randomization
- *                  of intermediate results during the ECP computations is
- *                  not needed (discouraged). See the documentation of
- *                  mbedtls_ecp_mul() for more.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
  * \param p_rng     The RNG context to be passed to \p f_rng. This may be
  *                  \c NULL if \p f_rng is \c NULL or doesn't need a
  *                  context argument.
@@ -428,8 +425,7 @@ int mbedtls_ecdh_read_public( mbedtls_ecdh_context *ctx,
  * \param buf       The buffer to write the generated shared key to. This
  *                  must be a writable buffer of size \p blen Bytes.
  * \param blen      The length of the destination buffer \p buf in Bytes.
- * \param f_rng     The RNG function, for blinding purposes. This may
- *                  b \c NULL if blinding isn't needed.
+ * \param f_rng     The RNG function to use. This must not be \c NULL.
  * \param p_rng     The RNG context. This may be \c NULL if \p f_rng
  *                  doesn't need a context argument.
  *
diff --git a/tests/suites/test_suite_ecdh.function b/tests/suites/test_suite_ecdh.function
index 6e8459dcb..94030d89d 100644
--- a/tests/suites/test_suite_ecdh.function
+++ b/tests/suites/test_suite_ecdh.function
@@ -85,7 +85,8 @@ void ecdh_primitive_random( int id )
                                               &mbedtls_test_rnd_pseudo_rand,
                                               &rnd_info ) == 0 );
     TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zB, &qA, &dB,
-                                      NULL, NULL ) == 0 );
+                                              &mbedtls_test_rnd_pseudo_rand,
+                                              &rnd_info ) == 0 );
 
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &zA, &zB ) == 0 );
 
@@ -106,11 +107,13 @@ void ecdh_primitive_testvec( int id, data_t * rnd_buf_A, char * xA_str,
     mbedtls_ecp_point qA, qB;
     mbedtls_mpi dA, dB, zA, zB, check;
     mbedtls_test_rnd_buf_info rnd_info_A, rnd_info_B;
+    mbedtls_test_rnd_pseudo_info rnd_info;
 
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecp_point_init( &qA ); mbedtls_ecp_point_init( &qB );
     mbedtls_mpi_init( &dA ); mbedtls_mpi_init( &dB );
     mbedtls_mpi_init( &zA ); mbedtls_mpi_init( &zB ); mbedtls_mpi_init( &check );
+    memset( &rnd_info, 0x00, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );
 
@@ -169,9 +172,13 @@ void ecdh_primitive_testvec( int id, data_t * rnd_buf_A, char * xA_str,
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &qB.Y, &check ) == 0 );
 
     TEST_ASSERT( mbedtls_mpi_read_string( &check, 16, z_str ) == 0 );
-    TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zA, &qB, &dA, NULL, NULL ) == 0 );
+    TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zA, &qB, &dA,
+                                              &mbedtls_test_rnd_pseudo_rand,
+                                              &rnd_info ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &zA, &check ) == 0 );
-    TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zB, &qA, &dB, NULL, NULL ) == 0 );
+    TEST_ASSERT( mbedtls_ecdh_compute_shared( &grp, &zB, &qA, &dB,
+                                              &mbedtls_test_rnd_pseudo_rand,
+                                              &rnd_info ) == 0 );
     TEST_ASSERT( mbedtls_mpi_cmp_mpi( &zB, &check ) == 0 );
 
 exit:
@@ -215,7 +222,8 @@ void ecdh_exchange( int id )
                                            &mbedtls_test_rnd_pseudo_rand,
                                            &rnd_info ) == 0 );
     TEST_ASSERT( mbedtls_ecdh_calc_secret( &cli, &res_len, res_buf, 1000,
-                                           NULL, NULL ) == 0 );
+                                           &mbedtls_test_rnd_pseudo_rand,
+                                           &rnd_info ) == 0 );
     TEST_ASSERT( len == res_len );
     TEST_ASSERT( memcmp( buf, res_buf, len ) == 0 );
 
@@ -235,12 +243,14 @@ void ecdh_restart( int id, data_t *dA, data_t *dB, data_t *z,
     const unsigned char *vbuf;
     size_t len;
     mbedtls_test_rnd_buf_info rnd_info_A, rnd_info_B;
+    mbedtls_test_rnd_pseudo_info rnd_info;
     int cnt_restart;
     mbedtls_ecp_group grp;
 
     mbedtls_ecp_group_init( &grp );
     mbedtls_ecdh_init( &srv );
     mbedtls_ecdh_init( &cli );
+    memset( &rnd_info, 0x00, sizeof( mbedtls_test_rnd_pseudo_info ) );
 
     rnd_info_A.fallback_f_rng = mbedtls_test_rnd_std_rand;
     rnd_info_A.fallback_p_rng = NULL;
@@ -315,7 +325,8 @@ void ecdh_restart( int id, data_t *dA, data_t *dB, data_t *z,
     cnt_restart = 0;
     do {
         ret = mbedtls_ecdh_calc_secret( &srv, &len, buf, sizeof( buf ),
-                                              NULL, NULL );
+                                        &mbedtls_test_rnd_pseudo_rand,
+                                        &rnd_info );
     } while( ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart );
 
     TEST_ASSERT( ret == 0 );
@@ -332,7 +343,8 @@ void ecdh_restart( int id, data_t *dA, data_t *dB, data_t *z,
     cnt_restart = 0;
     do {
         ret = mbedtls_ecdh_calc_secret( &cli, &len, buf, sizeof( buf ),
-                                              NULL, NULL );
+                                        &mbedtls_test_rnd_pseudo_rand,
+                                        &rnd_info );
     } while( ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart );
 
     TEST_ASSERT( ret == 0 );