diff --git a/src/chars.c b/src/chars.c
index 2745ef33..8eed0e54 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -594,8 +594,7 @@ char *mbstrcasestr(const char *haystack, const char *needle)
 
 	for (; *haystack != '\0' && haystack_len >= needle_len;
 		haystack += move_mbright(haystack, 0), haystack_len--) {
-	    if (mbstrncasecmp(haystack, needle, needle_len) == 0 &&
-			mblen(haystack, MB_CUR_MAX) > 0)
+	    if (mbstrncasecmp(haystack, needle, needle_len) == 0)
 		return (char *)haystack;
 	}
 
@@ -687,8 +686,7 @@ char *mbrevstrcasestr(const char *haystack, const char *needle, const
 
 	while (TRUE) {
 	    if (rev_start_len >= needle_len &&
-			mbstrncasecmp(rev_start, needle, needle_len) == 0 &&
-			mblen(rev_start, MB_CUR_MAX) > 0)
+			mbstrncasecmp(rev_start, needle, needle_len) == 0)
 		return (char *)rev_start;
 
 	    /* If we've reached the head of the haystack, we found nothing. */