diff --git a/programs/test/benchmark.c b/programs/test/benchmark.c
index e580fb2..148e6da 100644
--- a/programs/test/benchmark.c
+++ b/programs/test/benchmark.c
@@ -827,6 +827,7 @@
 
         mbedtls_dhm_context dhm;
         size_t olen;
+        size_t n;
         for( i = 0; (size_t) i < sizeof( dhm_sizes ) / sizeof( dhm_sizes[0] ); i++ )
         {
             mbedtls_dhm_init( &dhm );
@@ -839,14 +840,14 @@
                 mbedtls_exit( 1 );
             }
 
-            dhm.len = mbedtls_mpi_size( &dhm.P );
-            mbedtls_dhm_make_public( &dhm, (int) dhm.len, buf, dhm.len, myrand, NULL );
+            n = mbedtls_mpi_size( &dhm.P );
+            mbedtls_dhm_make_public( &dhm, (int) n, buf, n, myrand, NULL );
             if( mbedtls_mpi_copy( &dhm.GY, &dhm.GX ) != 0 )
                 mbedtls_exit( 1 );
 
             mbedtls_snprintf( title, sizeof( title ), "DHE-%d", dhm_sizes[i] );
             TIME_PUBLIC( title, "handshake",
-                    ret |= mbedtls_dhm_make_public( &dhm, (int) dhm.len, buf, dhm.len,
+                    ret |= mbedtls_dhm_make_public( &dhm, (int) n, buf, n,
                                             myrand, NULL );
                     ret |= mbedtls_dhm_calc_secret( &dhm, buf, sizeof( buf ), &olen, myrand, NULL ) );