diff --git a/match.c b/match.c
index 10e60bd3..45b39b57 100644
--- a/match.c
+++ b/match.c
@@ -293,6 +293,7 @@ static void hash_search(int f,struct sum_struct *s,
 			 && (!updating_basis_file || s->sums[want_i].offset >= offset
 			  || s->sums[want_i].flags & SUMFLG_SAME_OFFSET)
 			 && sum == s->sums[want_i].sum1
+			 && l == s->sums[want_i].len
 			 && memcmp(sum2, sum2_at(s, want_i), s->s2length) == 0) {
 				/* we've found an adjacent match - the RLL coder
 				 * will be happy */