diff --git a/programs/pkey/ecdsa.c b/programs/pkey/ecdsa.c
index b474060..8455bb5 100644
--- a/programs/pkey/ecdsa.c
+++ b/programs/pkey/ecdsa.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_ECDSA_C) && \
     defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_CTR_DRBG_C)
@@ -98,7 +101,8 @@
 
 int main( int argc, char *argv[] )
 {
-    int ret;
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
     mbedtls_ecdsa_context ctx_sign, ctx_verify;
     mbedtls_entropy_context entropy;
     mbedtls_ctr_drbg_context ctr_drbg;
@@ -115,7 +119,6 @@
 
     memset( sig, 0, sizeof( sig ) );
     memset( message, 0x25, sizeof( message ) );
-    ret = 1;
 
     if( argc != 1 )
     {
@@ -213,8 +216,6 @@
         goto exit;
     }
 
-    ret = 0;
-
     /*
      * Verify signature
      */
@@ -231,6 +232,8 @@
 
     mbedtls_printf( " ok\n" );
 
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
 exit:
 
 #if defined(_WIN32)
@@ -243,7 +246,7 @@
     mbedtls_ctr_drbg_free( &ctr_drbg );
     mbedtls_entropy_free( &entropy );
 
-    return( ret );
+    return( exit_code );
 }
 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C &&
           ECPARAMS */