diff --git a/extra/benchmark/nbody-simd/nbody-simd.factor b/extra/benchmark/nbody-simd/nbody-simd.factor
index fb30ce7eaf..e83f3ddc01 100644
--- a/extra/benchmark/nbody-simd/nbody-simd.factor
+++ b/extra/benchmark/nbody-simd/nbody-simd.factor
@@ -49,7 +49,7 @@ STRUCT: body
 TUPLE: nbody-system { bodies struct-array read-only } ;
 
 : init-bodies ( bodies -- )
-    [ first ] [ double-4{ 0 0 0 0 } [ [ velocity>> ] [ mass>> ] bi v*n v+ ] reduce ] bi
+    [ first ] [ [ [ velocity>> ] [ mass>> ] bi v*n ] [ v+ ] map-reduce ] bi
     offset-momentum drop ; inline
 
 : <nbody-system> ( -- system )