diff --git a/programs/pkey/pk_sign.c b/programs/pkey/pk_sign.c
index 55df95e..240be6b 100644
--- a/programs/pkey/pk_sign.c
+++ b/programs/pkey/pk_sign.c
@@ -30,9 +30,11 @@
 #else
 #include <stdio.h>
 #include <stdlib.h>
-#define mbedtls_snprintf   snprintf
-#define mbedtls_printf     printf
-#endif
+#define mbedtls_snprintf        snprintf
+#define mbedtls_printf          printf
+#define MBEDTLS_EXTI_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
 
 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) ||  \
     !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_MD_C) || \
@@ -61,6 +63,7 @@
 {
     FILE *f;
     int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
     mbedtls_pk_context pk;
     mbedtls_entropy_context entropy;
     mbedtls_ctr_drbg_context ctr_drbg;
@@ -134,14 +137,12 @@
 
     if( ( f = fopen( filename, "wb+" ) ) == NULL )
     {
-        ret = 1;
         mbedtls_printf( " failed\n  ! Could not create %s\n\n", filename );
         goto exit;
     }
 
     if( fwrite( buf, 1, olen, f ) != olen )
     {
-        ret = 1;
         mbedtls_printf( "failed\n  ! fwrite failed\n\n" );
         fclose( f );
         goto exit;
@@ -151,13 +152,15 @@
 
     mbedtls_printf( "\n  . Done (created \"%s\")\n\n", filename );
 
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
 exit:
     mbedtls_pk_free( &pk );
     mbedtls_ctr_drbg_free( &ctr_drbg );
     mbedtls_entropy_free( &entropy );
 
 #if defined(MBEDTLS_ERROR_C)
-    if( ret != 0 )
+    if( exit_code != MBEDTLS_EXIT_SUCCESS )
     {
         mbedtls_strerror( ret, (char *) buf, sizeof(buf) );
         mbedtls_printf( "  !  Last error was: %s\n", buf );
@@ -169,7 +172,7 @@
     fflush( stdout ); getchar();
 #endif
 
-    return( ret ? EXIT_FAILURE : EXIT_SUCCESS );
+    return( exit_code );
 }
 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C &&
           MBEDTLS_SHA256_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&