diff --git a/src/liblzma/lz/lz_encoder_mf.c b/src/liblzma/lz/lz_encoder_mf.c
index 6dc39f4..7852077 100644
--- a/src/liblzma/lz/lz_encoder_mf.c
+++ b/src/liblzma/lz/lz_encoder_mf.c
@@ -632,9 +632,8 @@
 	uint32_t len_best = 2;
 
 	if (delta2 < mf->cyclic_size && *(cur - delta2) == *cur) {
-		for ( ; len_best != len_limit; ++len_best)
-			if (*(cur + len_best - delta2) != cur[len_best])
-				break;
+		len_best = lzma_memcmplen(
+				cur, cur - delta2, len_best, len_limit);
 
 		matches[0].len = len_best;
 		matches[0].dist = delta2 - 1;