diff --git a/programs/pkey/gen_key.c b/programs/pkey/gen_key.c
index a7f5c90a6..9a98fda56 100644
--- a/programs/pkey/gen_key.c
+++ b/programs/pkey/gen_key.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) && \
     defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_CTR_DRBG_C)
@@ -186,7 +189,8 @@ static int write_private_key( mbedtls_pk_context *key, const char *output_file )
 
 int main( int argc, char *argv[] )
 {
-    int ret = 0;
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
     mbedtls_pk_context key;
     char buf[1024];
     int i;
@@ -214,7 +218,6 @@ int main( int argc, char *argv[] )
     if( argc == 0 )
     {
     usage:
-        ret = 1;
         mbedtls_printf( USAGE );
 #if defined(MBEDTLS_ECP_C)
         mbedtls_printf( " available ec_curve values:\n" );
@@ -222,7 +225,7 @@ int main( int argc, char *argv[] )
         mbedtls_printf( "    %s (default)\n", curve_info->name );
         while( ( ++curve_info )->name != NULL )
             mbedtls_printf( "    %s\n", curve_info->name );
-#endif
+#endif /* MBEDTLS_ECP_C */
         goto exit;
     }
 
@@ -411,9 +414,11 @@ int main( int argc, char *argv[] )
 
     mbedtls_printf( " ok\n" );
 
+    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 ) );
@@ -436,7 +441,7 @@ exit:
     fflush( stdout ); getchar();
 #endif
 
-    return( ret );
+    return( exit_code );
 }
 #endif /* MBEDTLS_PK_WRITE_C && MBEDTLS_PEM_WRITE_C && MBEDTLS_FS_IO &&
         * MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */