diff --git a/tests/t-reader.c b/tests/t-reader.c
index 53118b5..2b6a40c 100644
--- a/tests/t-reader.c
+++ b/tests/t-reader.c
@@ -1,207 +1,208 @@
 /* t-reader.c - basic tests for the reader object
  *      Copyright (C) 2017 g10 Code GmbH
  *
  * This file is part of KSBA.
  *
  * KSBA is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * KSBA is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include <time.h>
 #include <errno.h>
 
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <gpg-error.h>
 
 #include "../src/ksba.h"
 #include "t-common.h"
 
 void
 test_fd(const char* path)
 {
   int fd = open (path, O_RDONLY);
   gpg_error_t err = 0;
   ksba_reader_t reader;
   ksba_cert_t cert;
 
   if (fd < 0)
     {
       perror ("open() failed");
       exit (1);
     }
 
   if ((err = ksba_reader_new (&reader)))
     {
       fprintf (stderr, "ksba_reader_new() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_reader_set_fd (reader, fd)))
     {
       fprintf (stderr, "ksba_reader_set_fd() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_new (&cert)))
     {
       fprintf (stderr, "ksba_cert_new() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_read_der (cert, reader)))
     {
       fprintf(stderr, "ksba_cert_read_der() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   ksba_cert_release (cert);
   ksba_reader_release (reader);
   close (fd);
 }
 
 void
 test_file(const char* path)
 {
   FILE* fp = fopen (path, "r");
   gpg_error_t err = 0;
   ksba_reader_t reader;
   ksba_cert_t cert;
 
   if (!fp)
     {
       perror ("fopen() failed");
       exit (1);
     }
 
   if ((err = ksba_reader_new (&reader)))
     {
       fprintf (stderr, "ksba_reader_new() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_reader_set_file (reader, fp)))
     {
       fprintf (stderr, "ksba_reader_set_fd() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_new (&cert)))
     {
       fprintf (stderr, "ksba_cert_new() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_read_der (cert, reader)))
     {
       fprintf(stderr, "ksba_cert_read_der() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   ksba_cert_release (cert);
   ksba_reader_release (reader);
   fclose (fp);
 }
 
 void
 test_mem(const char* path)
 {
   int fd = open (path, O_RDONLY);
   gpg_error_t err = 0;
   ksba_reader_t reader;
   ksba_cert_t cert;
   char *mem = NULL;
   ssize_t ret = 0;
   size_t p = 0;
   struct stat st;
 
   if (fd < 0)
     {
       perror ("fopen() failed");
       exit (1);
     }
 
   if (fstat (fd, &st))
     {
       fprintf (stderr, "fstat() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   mem = xmalloc(st.st_size);
 
   while (p < st.st_size && (ret = read(fd, mem + p, st.st_size - p)))
     {
       if (ret < 0)
         {
           fprintf (stderr, "read() failed: %s\n", gpg_strerror (err));
           exit (1);
         }
       p += ret;
     }
 
   if ((err = ksba_reader_new (&reader)))
     {
       exit (1);
     }
 
   if ((err = ksba_reader_set_mem (reader, mem, st.st_size)))
     {
       fprintf (stderr, "ksba_reader_set_mem() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_new (&cert)))
     {
       fprintf (stderr, "ksba_cert_new() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   if ((err = ksba_cert_read_der (cert, reader)))
     {
       fprintf(stderr, "ksba_cert_read_der() failed: %s\n", gpg_strerror (err));
       exit (1);
     }
 
   ksba_cert_release (cert);
   ksba_reader_release (reader);
   xfree (mem);
   close (fd);
 }
 
 int
 main (int argc, char **argv)
 {
   if (argc == 1)
     {
       test_fd (prepend_srcdir ("cert_g10code_test1.der"));
       test_file (prepend_srcdir ("cert_g10code_test1.der"));
       test_mem (prepend_srcdir ("cert_g10code_test1.der"));
     }
   else
     {
-      for (int i = 1; i < argc; ++i)
+      int i;
+      for (i = 1; i < argc; ++i)
         {
           test_fd (argv[i]);
           test_file (argv[i]);
           test_mem (argv[i]);
         }
     }
 
   return 0;
 }