diff --git a/lib/glibcompat.c b/lib/glibcompat.c
index 27d81a247..8a5e2e91a 100644
--- a/lib/glibcompat.c
+++ b/lib/glibcompat.c
@@ -297,3 +297,32 @@ mc_g_string_dup (const GString * s)
 }
 
 /* --------------------------------------------------------------------------------------------- */
+
+/**
+ * mc_g_string_append_c_len:
+ * @s: (not nullable): the destination #GString.
+ * @c: the byte to append onto the end of @s
+ * @len: the number of bytes @c to append onto the end of @s
+ * @return: @s
+ *
+ * Adds @len bytes @c onto the end of @s.
+ *
+ * There is no such API in GLib2.
+ */
+GString *
+mc_g_string_append_c_len (GString * s, gchar c, guint len)
+{
+    g_return_val_if_fail (s != NULL, NULL);
+
+    if (len != 0)
+    {
+        guint s_len = s->len;
+
+        g_string_set_size (s, s->len + len);
+        memset (s->str + s_len, (unsigned char) c, len);
+    }
+
+    return s;
+}
+
+/* --------------------------------------------------------------------------------------------- */
diff --git a/lib/glibcompat.h b/lib/glibcompat.h
index e2f84f5d9..9ab3b47f5 100644
--- a/lib/glibcompat.h
+++ b/lib/glibcompat.h
@@ -40,6 +40,9 @@ GString *mc_g_string_copy (GString * dest, const GString * src);
 /* There is no such API in GLib2 */
 GString *mc_g_string_dup (const GString * s);
 
+/* There is no such API in GLib2 */
+GString *mc_g_string_append_c_len (GString * s, gchar c, guint len);
+
 /*** inline functions ****************************************************************************/
 
 #endif /* MC_GLIBCOMPAT_H */
diff --git a/lib/strutil/strutil.c b/lib/strutil/strutil.c
index 4e24e7f0a..7f0290b0a 100644
--- a/lib/strutil/strutil.c
+++ b/lib/strutil/strutil.c
@@ -153,9 +153,7 @@ _str_convert (GIConv coder, const char *string, int size, GString * buffer)
             case G_CONVERT_ERROR_NO_CONVERSION:
                 /* Conversion between the requested character sets is not supported. */
                 g_free (tmp_buff);
-                tmp_buff = g_strnfill (strlen (string), '?');
-                g_string_append (buffer, tmp_buff);
-                g_free (tmp_buff);
+                mc_g_string_append_c_len (buffer, '?', strlen (string));
                 return ESTR_FAILURE;
 
             case G_CONVERT_ERROR_ILLEGAL_SEQUENCE:
@@ -186,12 +184,7 @@ _str_convert (GIConv coder, const char *string, int size, GString * buffer)
                 g_string_append (buffer, tmp_buff);
                 g_free (tmp_buff);
                 if ((int) bytes_read < left)
-                {
-                    left = left - bytes_read;
-                    tmp_buff = g_strnfill (left, '?');
-                    g_string_append (buffer, tmp_buff);
-                    g_free (tmp_buff);
-                }
+                    mc_g_string_append_c_len (buffer, '?', left - bytes_read);
                 return ESTR_PROBLEM;
 
             case G_CONVERT_ERROR_BAD_URI:      /* Don't know how handle this error :( */