diff --git a/extra/sequences/lib/lib.factor b/extra/sequences/lib/lib.factor
index e46ce3b107..9aac0a50bd 100755
--- a/extra/sequences/lib/lib.factor
+++ b/extra/sequences/lib/lib.factor
@@ -140,3 +140,6 @@ PRIVATE>
 : ?second ( seq -- second/f ) 1 swap ?nth ; inline
 : ?third ( seq -- third/f ) 2 swap ?nth ; inline
 : ?fourth ( seq -- fourth/f ) 3 swap ?nth ; inline
+
+: accumulator ( quot -- quot vec )
+    V{ } clone [ [ push ] curry compose ] keep ;