diff --git a/basis/checksums/adler-32/adler-32.factor b/basis/checksums/adler-32/adler-32.factor
index f66860dc63..1937503dd9 100644
--- a/basis/checksums/adler-32/adler-32.factor
+++ b/basis/checksums/adler-32/adler-32.factor
@@ -13,3 +13,5 @@ M: adler-32 checksum-bytes ( bytes checksum -- value )
     [ sum 1 + ]
     [ [ dup length [1,b] <reversed> v. ] [ length ] bi + ] bi
     [ adler-32-modulus mod ] bi@ 16 shift bitor ;
+
+INSTANCE: adler-32 checksum