diff --git a/programs/pkey/key_app_writer.c b/programs/pkey/key_app_writer.c
index 5f7d2dd..0292a1d 100644
--- a/programs/pkey/key_app_writer.c
+++ b/programs/pkey/key_app_writer.c
@@ -29,8 +29,11 @@
 #include "mbedtls/platform.h"
 #else
 #include <stdio.h>
-#define mbedtls_printf     printf
-#endif
+#include <stdlib.h>
+#define mbedtls_printf          printf
+#define MBEDTLS_EXTI_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
 
 #if defined(MBEDTLS_PK_WRITE_C) && defined(MBEDTLS_FS_IO)
 #include "mbedtls/error.h"
@@ -189,7 +192,8 @@
 
 int main( int argc, char *argv[] )
 {
-    int ret = 0;
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
     char buf[1024];
     int i;
     char *p, *q;
@@ -210,7 +214,6 @@
     if( argc == 0 )
     {
     usage:
-        ret = 1;
         mbedtls_printf( USAGE );
         goto exit;
     }
@@ -403,9 +406,11 @@
         write_private_key( &key, opt.output_file );
     }
 
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
 exit:
 
-    if( ret != 0 && ret != 1)
+    if( exit_code != MBEDTLS_EXIT_SUCCESS )
     {
 #ifdef MBEDTLS_ERROR_C
         mbedtls_strerror( ret, buf, sizeof( buf ) );
@@ -426,6 +431,6 @@
     fflush( stdout ); getchar();
 #endif
 
-    return( ret );
+    return( exit_code );
 }
 #endif /* MBEDTLS_PK_WRITE_C && MBEDTLS_FS_IO */