diff --git a/programs/pkey/key_app_writer.c b/programs/pkey/key_app_writer.c
index 9d120772a..52b0f8e74 100644
--- a/programs/pkey/key_app_writer.c
+++ b/programs/pkey/key_app_writer.c
@@ -76,7 +76,7 @@
 #define OUTPUT_FORMAT_DER              1
 
 #define USAGE \
-    "\n usage: key_app param=<>...\n"                   \
+    "\n usage: key_app_writer param=<>...\n"            \
     "\n acceptable parameters:\n"                       \
     "    mode=private|public default: none\n"           \
     "    filename=%%s         default: keyfile.key\n"   \
@@ -190,17 +190,23 @@ static int write_private_key( mbedtls_pk_context *key, const char *output_file )
 int main( int argc, char *argv[] )
 {
     int ret = 0;
-    mbedtls_pk_context key;
     char buf[1024];
     int i;
     char *p, *q;
 
+    mbedtls_pk_context key;
+    mbedtls_mpi N, P, Q, D, E, DP, DQ, QP;
+
     /*
      * Set to sane values
      */
     mbedtls_pk_init( &key );
     memset( buf, 0, sizeof( buf ) );
 
+    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 );
+
     if( argc == 0 )
     {
     usage:
@@ -300,14 +306,22 @@ int main( int argc, char *argv[] )
         if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_RSA )
         {
             mbedtls_rsa_context *rsa = mbedtls_pk_rsa( key );
-            mbedtls_mpi_write_file( "N:  ",  &rsa->N,  16, NULL );
-            mbedtls_mpi_write_file( "E:  ",  &rsa->E,  16, NULL );
-            mbedtls_mpi_write_file( "D:  ",  &rsa->D,  16, NULL );
-            mbedtls_mpi_write_file( "P:  ",  &rsa->P,  16, NULL );
-            mbedtls_mpi_write_file( "Q:  ",  &rsa->Q,  16, NULL );
-            mbedtls_mpi_write_file( "DP: ",  &rsa->DP, 16, NULL );
-            mbedtls_mpi_write_file( "DQ:  ", &rsa->DQ, 16, NULL );
-            mbedtls_mpi_write_file( "QP:  ", &rsa->QP, 16, NULL );
+
+            if( ( ret = mbedtls_rsa_export    ( rsa, &N, &P, &Q, &D, &E ) ) != 0 ||
+                ( ret = mbedtls_rsa_export_crt( rsa, &DP, &DQ, &QP ) )      != 0 )
+            {
+                mbedtls_printf( " failed\n  ! could not export RSA parameters\n\n" );
+                goto exit;
+            }
+
+            mbedtls_mpi_write_file( "N:  ",  &N,  16, NULL );
+            mbedtls_mpi_write_file( "E:  ",  &E,  16, NULL );
+            mbedtls_mpi_write_file( "D:  ",  &D,  16, NULL );
+            mbedtls_mpi_write_file( "P:  ",  &P,  16, NULL );
+            mbedtls_mpi_write_file( "Q:  ",  &Q,  16, NULL );
+            mbedtls_mpi_write_file( "DP: ",  &DP, 16, NULL );
+            mbedtls_mpi_write_file( "DQ:  ", &DQ, 16, NULL );
+            mbedtls_mpi_write_file( "QP:  ", &QP, 16, NULL );
         }
         else
 #endif
@@ -353,8 +367,15 @@ int main( int argc, char *argv[] )
         if( mbedtls_pk_get_type( &key ) == MBEDTLS_PK_RSA )
         {
             mbedtls_rsa_context *rsa = mbedtls_pk_rsa( key );
-            mbedtls_mpi_write_file( "N: ", &rsa->N, 16, NULL );
-            mbedtls_mpi_write_file( "E: ", &rsa->E, 16, NULL );
+
+            if( ( ret = mbedtls_rsa_export( rsa, &N, NULL, NULL,
+                                            NULL, &E ) ) != 0 )
+            {
+                mbedtls_printf( " failed\n  ! could not export RSA parameters\n\n" );
+                goto exit;
+            }
+            mbedtls_mpi_write_file( "N: ", &N, 16, NULL );
+            mbedtls_mpi_write_file( "E: ", &E, 16, NULL );
         }
         else
 #endif
@@ -394,6 +415,10 @@ exit:
 #endif
     }
 
+    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 );
+
     mbedtls_pk_free( &key );
 
 #if defined(_WIN32)