diff --git a/src/fileio.c b/src/fileio.c
index c21035c..e05fb54 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1491,7 +1491,7 @@
 			else
 			{
 			    u8c = utf_ptr2char(src);
-			    if (u8c > 0xffff)
+			    if (u8c > 0xffff || (*src >= 0x80 && bytelen == 1))
 				found_bad = TRUE;
 			    ucs2buf[0] = u8c;
 			    ucs2len = 1;