diff --git a/programs/pkey/pk_verify.c b/programs/pkey/pk_verify.c
index d35d17f..24fcd37 100644
--- a/programs/pkey/pk_verify.c
+++ b/programs/pkey/pk_verify.c
@@ -29,9 +29,12 @@
 #include "mbedtls/platform.h"
 #else
 #include <stdio.h>
-#define mbedtls_snprintf   snprintf
-#define mbedtls_printf     printf
-#endif
+#include <stdlib.h>
+#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_MD_C) || \
     !defined(MBEDTLS_SHA256_C) || !defined(MBEDTLS_PK_PARSE_C) ||   \
@@ -56,6 +59,7 @@
 {
     FILE *f;
     int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
     size_t i;
     mbedtls_pk_context pk;
     unsigned char hash[32];
@@ -87,7 +91,6 @@
     /*
      * Extract the signature from the file
      */
-    ret = 1;
     mbedtls_snprintf( filename, sizeof(filename), "%s.sig", argv[2] );
 
     if( ( f = fopen( filename, "rb" ) ) == NULL )
@@ -125,13 +128,13 @@
 
     mbedtls_printf( "\n  . OK (the signature is valid)\n\n" );
 
-    ret = 0;
+    exit_code = MBEDTLS_EXIT_SUCCESS;
 
 exit:
     mbedtls_pk_free( &pk );
 
 #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 );
@@ -143,7 +146,7 @@
     fflush( stdout ); getchar();
 #endif
 
-    return( ret );
+    return( exit_code );
 }
 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_SHA256_C &&
           MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO */