diff --git a/extra/bloom-filters/bloom-filters.factor b/extra/bloom-filters/bloom-filters.factor
index e5e14d48fb..8dbdd3e24f 100644
--- a/extra/bloom-filters/bloom-filters.factor
+++ b/extra/bloom-filters/bloom-filters.factor
@@ -109,6 +109,7 @@ PRIVATE>
 ! See "Bloom Filters in Probabilistic Verification" by Peter C.
 ! Dillinger and Panagiotis Manolios, section 5.2, "Enhanced
 ! Double Hashing":
+! http://www.ccs.neu.edu/home/pete/research/bloom-filters-verification.html
 ! http://www.cc.gatech.edu/~manolios/research/bloom-filters-verification.html
 : combine-hashcodes ( index hash0 hash1 -- hash )
     { fixnum fixnum fixnum } declare