diff --git a/tools/gpgtar-create.c b/tools/gpgtar-create.c
index f6a80a1a5..a7aae3b3f 100644
--- a/tools/gpgtar-create.c
+++ b/tools/gpgtar-create.c
@@ -36,7 +36,6 @@
 # include <pwd.h>
 # include <grp.h>
 #endif /*!HAVE_W32_SYSTEM*/
-#include <assert.h>
 
 #include "../common/i18n.h"
 #include "../common/exectool.h"
@@ -114,7 +113,7 @@ fillup_entry_w32 (tar_header_t hdr)
   for (p=hdr->name; *p; p++)
     if (*p == '/')
       *p = '\\';
-  wfname = utf8_to_wchar (hdr->name);
+  wfname = gpgrt_fname_to_wchar (hdr->name);
   for (p=hdr->name; *p; p++)
     if (*p == '\\')
       *p = '/';
@@ -345,7 +344,7 @@ scan_directory (const char *dname, scanctrl_t scanctrl)
     for (p=fname; *p; p++)
       if (*p == '/')
         *p = '\\';
-    wfname = utf8_to_wchar (fname);
+    wfname = gpgrt_fname_to_wchar (fname);
     xfree (fname);
     if (!wfname)
       {
@@ -448,7 +447,7 @@ scan_recursive (const char *dname, scanctrl_t scanctrl)
     }
   scanctrl->nestlevel++;
 
-  assert (scanctrl->flist_tail);
+  log_assert (scanctrl->flist_tail);
   start_tail = scanctrl->flist_tail;
   scan_directory (dname, scanctrl);
   stop_tail = scanctrl->flist_tail;
@@ -903,7 +902,7 @@ write_file (estream_t stream, tar_header_t hdr)
 
   if (hdr->typeflag == TF_REGULAR)
     {
-      infp = es_fopen (hdr->name, "rb");
+      infp = es_fopen (hdr->name, "rb,sysopen");
       if (!infp)
         {
           err = gpg_error_from_syserror ();
@@ -1152,7 +1151,7 @@ gpgtar_create (char **inpattern, const char *files_from, int null_names,
       if (!strcmp (opt.outfile, "-"))
         outstream = es_stdout;
       else
-        outstream = es_fopen (opt.outfile, "wb");
+        outstream = es_fopen (opt.outfile, "wb,sysopen");
       if (!outstream)
         {
           err = gpg_error_from_syserror ();
diff --git a/tools/gpgtar-extract.c b/tools/gpgtar-extract.c
index e9baada4e..5fad893c5 100644
--- a/tools/gpgtar-extract.c
+++ b/tools/gpgtar-extract.c
@@ -28,7 +28,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
-#include <assert.h>
 
 #include "../common/i18n.h"
 #include "../common/exectool.h"
@@ -98,9 +97,9 @@ extract_regular (estream_t stream, const char *dirname,
 
 
   if (opt.dry_run)
-    outfp = es_fopenmem (0, "wb");
+    outfp = es_fopen ("/dev/null", "wb");
   else
-    outfp = es_fopen (fname, "wb");
+    outfp = es_fopen (fname, "wb,sysopen");
   if (!outfp)
     {
       err = gpg_error_from_syserror ();
@@ -333,7 +332,7 @@ gpgtar_extract (const char *filename, int decrypt)
       if (!strcmp (filename, "-"))
         stream = es_stdin;
       else
-        stream = es_fopen (filename, "rb");
+        stream = es_fopen (filename, "rb,sysopen");
       if (!stream)
         {
           err = gpg_error_from_syserror ();
diff --git a/tools/gpgtar.c b/tools/gpgtar.c
index c2f24ecab..c15f3dcd0 100644
--- a/tools/gpgtar.c
+++ b/tools/gpgtar.c
@@ -34,7 +34,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <assert.h>
 
 #define INCLUDED_BY_MAIN_MODULE 1
 #include "../common/util.h"
@@ -259,7 +258,7 @@ shell_parse_stringlist (const char *str, strlist_t *r_list)
           break;
 
         case doublequote:
-          assert (s > str || !"cannot be quoted at first char");
+          log_assert (s > str || !"cannot be quoted at first char");
           if (*s == doublequote && *(s - 1) != '\\')
             quoted = unquoted;
           else
@@ -267,7 +266,7 @@ shell_parse_stringlist (const char *str, strlist_t *r_list)
           break;
 
         default:
-          assert (! "reached");
+          log_assert (! "reached");
         }
     }