diff --git a/programs/pkey/rsa_sign.c b/programs/pkey/rsa_sign.c
index affbf7a..5f61561 100644
--- a/programs/pkey/rsa_sign.c
+++ b/programs/pkey/rsa_sign.c
@@ -61,8 +61,14 @@
     unsigned char hash[32];
     unsigned char buf[MBEDTLS_MPI_MAX_SIZE];
     char filename[512];
+    mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
 
     mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
+
+    mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
+    mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E ); mbedtls_mpi_init( &DP );
+    mbedtls_mpi_init( &DQ ); mbedtls_mpi_init( &QP );
+
     ret = 1;
 
     if( argc != 2 )
@@ -87,24 +93,35 @@
         goto exit;
     }
 
-    if( ( ret = mbedtls_mpi_read_file( &rsa.N , 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.E , 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.D , 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.P , 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.Q , 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.DP, 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.DQ, 16, f ) ) != 0 ||
-        ( ret = mbedtls_mpi_read_file( &rsa.QP, 16, f ) ) != 0 )
+    if( ( ret = mbedtls_mpi_read_file( &N , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &E , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &D , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &P , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &Q , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &DP , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &DQ , 16, f ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_file( &QP , 16, f ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! mbedtls_mpi_read_file returned %d\n\n", ret );
         fclose( f );
         goto exit;
     }
-
-    rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3;
-
     fclose( f );
 
+    if( ( ret = mbedtls_rsa_import( &rsa, &N, &P, &Q, &D, &E ) ) != 0 )
+    {
+        mbedtls_printf( " failed\n  ! mbedtls_rsa_import returned %d\n\n",
+                        ret );
+        goto exit;
+    }
+
+    if( ( ret = mbedtls_rsa_complete( &rsa, NULL, NULL ) ) != 0 )
+    {
+        mbedtls_printf( " failed\n  ! mbedtls_rsa_complete returned %d\n\n",
+                        ret );
+        goto exit;
+    }
+
     mbedtls_printf( "\n  . Checking the private key" );
     fflush( stdout );
     if( ( ret = mbedtls_rsa_check_privkey( &rsa ) ) != 0 )
@@ -113,6 +130,14 @@
         goto exit;
     }
 
+    /* Although we're not using them, verify CRT parameters */
+    if( ( ret = mbedtls_rsa_check_crt( &rsa, &DP, &DQ, &QP ) ) != 0 )
+    {
+        mbedtls_printf( " failed\n  ! mbedtls_rsa_check_crt returned %d\n\n",
+                        ret );
+        goto exit;
+    }
+
     /*
      * Compute the SHA-256 hash of the input file,
      * then calculate the RSA signature of the hash.
@@ -158,6 +183,9 @@
 exit:
 
     mbedtls_rsa_free( &rsa );
+    mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
+    mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E ); mbedtls_mpi_free( &DP );
+    mbedtls_mpi_free( &DQ ); mbedtls_mpi_free( &QP );
 
 #if defined(_WIN32)
     mbedtls_printf( "  + Press Enter to exit this program.\n" );