diff --git a/src/ui/inputwin.c b/src/ui/inputwin.c
index d19d8719..ac7cf817 100644
--- a/src/ui/inputwin.c
+++ b/src/ui/inputwin.c
@@ -373,6 +373,10 @@ _inp_offset_to_col(char* str, int offset)
     while (i < offset && str[i] != '\0') {
         gunichar uni = g_utf8_get_char(&str[i]);
         size_t ch_len = mbrlen(&str[i], MB_CUR_MAX, NULL);
+        if ((ch_len == (size_t)-2) || (ch_len == (size_t)-1)) {
+            i++;
+            continue;
+        }
         i += ch_len;
         col++;
         if (g_unichar_iswide(uni)) {