diff --git a/programs/x509/load_roots.c b/programs/x509/load_roots.c
index ba398f9..6a40949 100644
--- a/programs/x509/load_roots.c
+++ b/programs/x509/load_roots.c
@@ -109,7 +109,6 @@
     mbedtls_x509_crt cas;
     int ret = 0;
     const char *const *cur;
-    char error_message[200];
 
     mbedtls_x509_crt_init( &cas );
 
@@ -118,9 +117,15 @@
         ret = mbedtls_x509_crt_parse_file( &cas, *cur );
         if( ret != 0 )
         {
+#if defined(MBEDTLS_ERROR_C) || defined(MBEDTLS_ERROR_STRERROR_DUMMY)
+            char error_message[200];
             mbedtls_strerror( ret, error_message, sizeof( error_message ) );
             printf( "\n%s: -0x%04x (%s)\n",
                     *cur, (unsigned) -ret, error_message );
+#else
+            printf( "\n%s: -0x%04x\n",
+                    *cur, (unsigned) -ret );
+#endif
             goto exit;
         }
     }