diff --git a/logging.c b/logging.c

index 9e86808..613ff4b 100644

--- a/logging.c

+++ b/logging.c

@@ -171,7 +171,14 @@ vsf_log_do_log_to_file(int fd, struct mystr* p_str)

       return;

     }

   }

-  str_replace_unprintable(p_str, '?');

+  if (tunable_wc_logs_enable)

+  {

+    str_replace_unprintable_with_hex_wc(p_str);

+  }

+  else

+  {

+    str_replace_unprintable_with_hex(p_str);

+  }

   str_append_char(p_str, '\n');

   /* Ignore write failure; maybe the disk filled etc. */

   (void) str_write_loop(p_str, fd);

diff --git a/parseconf.c b/parseconf.c

index 3cfe7da..3729818 100644

--- a/parseconf.c

+++ b/parseconf.c

@@ -113,6 +113,7 @@ parseconf_bool_array[] =

   { "allow_writeable_chroot", &tunable_allow_writeable_chroot },

   { "better_stou", &tunable_better_stou },

   { "log_die", &tunable_log_die },

+  { "wc_logs_enable", &tunable_wc_logs_enable },

   { 0, 0 }

 };

diff --git a/str.c b/str.c

index 82b8ae4..c03e7d8 100644

--- a/str.c

+++ b/str.c

@@ -20,6 +20,11 @@

 #include "utility.h"

 #include "sysutil.h"

+#include <stdio.h>

+#include <string.h>

+#include <wchar.h>

+#include <wctype.h>

+

 /* File local functions */

 static void str_split_text_common(struct mystr* p_src, struct mystr* p_rhs,

                                   const char* p_text, int is_reverse);

@@ -723,6 +728,102 @@ str_replace_unprintable(struct mystr* p_str, char new_char)

   }

 }

+void

+str_replace_unprintable_with_hex(struct mystr* p_str)

+{

+  unsigned int ups_size = sizeof(unsigned int) * (p_str->len);

+  if (ups_size < p_str->len)

+  {

+    str_replace_unprintable(p_str, '?');

+    str_append_text(p_str, ": BUG: string is too long");

+    bug(p_str->p_buf);

+  }

+  unsigned int* ups = vsf_sysutil_malloc(ups_size);

+  unsigned int up_count = 0;

+  for (unsigned int i=0; i < p_str->len; i++)

+  {

+    if (!vsf_sysutil_isprint(p_str->p_buf[i]))

+    {

+      ups[up_count++] = i;

+    }

+  }

+  str_replace_positions_with_hex(p_str, ups, up_count);

+  vsf_sysutil_free(ups);

+}

+

+void str_replace_unprintable_with_hex_wc(struct mystr* p_str)

+{

+  unsigned int ups_size = sizeof(unsigned int) * (p_str->len);

+  if (ups_size < p_str->len)

+  {

+    str_replace_unprintable(p_str, '?');

+    str_append_text(p_str, ": BUG: string is too long");

+    bug(p_str->p_buf);

+  }

+  unsigned int* ups = vsf_sysutil_malloc(ups_size);

+  unsigned int up_count = 0;

+

+  size_t current = 0;

+  wchar_t pwc;

+  mbstate_t ps;

+  memset(&ps, 0, sizeof(ps));

+  ssize_t len = 0;

+  while ((len = mbrtowc(&pwc, p_str->p_buf, p_str->len - current, &ps)) > 0)

+  {

+    if (!iswprint(pwc))

+    {

+      for (int i = 0; i < len; i++)

+      {

+        ups[up_count++] = current++;

+      }

+    }

+    else

+    {

+      current += len;

+    }

+  }

+  if (len < 0)

+  {

+    while (current < p_str->len)

+    {

+      ups[up_count++] = current++;

+    }

+  }

+  str_replace_positions_with_hex(p_str, ups, up_count);

+  vsf_sysutil_free(ups);

+}

+

+void

+str_replace_positions_with_hex(struct mystr* p_str, const unsigned int* poss, const unsigned int pos_count)

+{

+  if (pos_count == 0)

+    return;

+

+  struct mystr tmp_str = INIT_MYSTR;

+  str_reserve(&tmp_str, p_str->len + 3 * pos_count);

+  unsigned int current = 0;

+

+  for (unsigned int i=0; i < pos_count; i++)

+  {

+    unsigned int pos = poss[i];

+

+    if (current < pos)

+      private_str_append_memchunk(&tmp_str, p_str->p_buf + current, pos - current);

+

+    char hex_buf[5];

+    memset(hex_buf, 0, sizeof(hex_buf));

+    sprintf(hex_buf, "\\x%02X", (unsigned char) p_str->p_buf[pos]);

+    str_append_text(&tmp_str, hex_buf);

+    current = pos + 1;

+  }

+

+  if (current < p_str->len)

+    private_str_append_memchunk(&tmp_str, p_str->p_buf + current, p_str->len - current);

+

+  str_copy(p_str, &tmp_str);

+  str_free(&tmp_str);

+}

+

 void

 str_basename (struct mystr* d_str, const struct mystr* path)

 {

diff --git a/str.h b/str.h

index 44270da..95a83b5 100644

--- a/str.h

+++ b/str.h

@@ -98,6 +98,10 @@ int str_contains_space(const struct mystr* p_str);

 int str_all_space(const struct mystr* p_str);

 int str_contains_unprintable(const struct mystr* p_str);

 void str_replace_unprintable(struct mystr* p_str, char new_char);

+void str_replace_unprintable_with_hex(struct mystr* p_str);

+void str_replace_unprintable_with_hex_wc(struct mystr* p_str);

+void str_replace_positions_with_hex(struct mystr* p_str, const unsigned int* poss,

+                                    const unsigned int pos_count);

 int str_atoi(const struct mystr* p_str);

 filesize_t str_a_to_filesize_t(const struct mystr* p_str);

 unsigned int str_octal_to_uint(const struct mystr* p_str);

diff --git a/tunables.c b/tunables.c

index a7ce9c8..c96c1ac 100644

--- a/tunables.c

+++ b/tunables.c

@@ -94,6 +94,7 @@ int tunable_seccomp_sandbox;

 int tunable_allow_writeable_chroot;

 int tunable_better_stou;

 int tunable_log_die;

+int tunable_wc_logs_enable;

 unsigned int tunable_accept_timeout;

 unsigned int tunable_connect_timeout;

@@ -244,6 +245,7 @@ tunables_load_defaults()

   tunable_allow_writeable_chroot = 0;

   tunable_better_stou = 0;

   tunable_log_die = 0;

+  tunable_wc_logs_enable = 0;

   tunable_accept_timeout = 60;

   tunable_connect_timeout = 60;

diff --git a/tunables.h b/tunables.h

index 029d645..8d50150 100644

--- a/tunables.h

+++ b/tunables.h

@@ -98,6 +98,7 @@ extern int tunable_better_stou;               /* Use better file name generation

 					       */

 extern int tunable_log_die;                   /* Log calls to die(), die2()

                                                * and bug() */

+extern int tunable_wc_logs_enable;            /* Allow non ASCII characters in logs */

 /* Integer/numeric defines */

 extern unsigned int tunable_accept_timeout;

diff --git a/vsftpd.conf.5 b/vsftpd.conf.5

index ce3fba3..815773f 100644

--- a/vsftpd.conf.5

+++ b/vsftpd.conf.5

@@ -735,6 +735,12 @@ If enabled, use CLONE_NEWPID and CLONE_NEWIPC to isolate processes to their

 ipc and pid namespaces. So separated processes can not interact with each other.

 Default: YES

+.TP

+.B wc_logs_enable

+If enabled, logs will be treated as wide-character strings and not just

+ASCII strings when filtering out non-printable characters.

+

+Default: NO

 .SH NUMERIC OPTIONS

 Below is a list of numeric options. A numeric option must be set to a non