diff --git a/guix/ui.scm b/guix/ui.scm
index 7920335928..0e60eb6edc 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -1291,23 +1291,36 @@ score, the more relevant OBJ is to REGEXPS."
                                     5             ;exact match
                                     1)))))
            regexps))
-
+    scores)
+
+  (define (update relevance weight scores)
+    (map + relevance
+           (map (lambda (score)
+                  (* weight score))
+                scores)))
+
+  (let ((scores (fold (lambda (metric relevance)
+                        (match metric
+                          ((field . weight)
+                           (match (field obj)
+                             (#f  relevance)
+                             ((? string? str)
+                              (update relevance weight (score str)))
+                             ((lst ...)
+                              (update relevance weight
+                                      (fold (lambda (elem prev)
+                                              (if (zero? (length elem))
+                                                  prev
+                                                  (map + elem prev)))
+                                            (make-list (length regexps) 0)
+                                            (map score lst)))
+                              )))))
+                      (make-list (length regexps) 0)
+                      metrics)))
     ;; Return zero if one of REGEXPS doesn't match.
     (if (any zero? scores)
         0
-        (reduce + 0 scores)))
-
-  (fold (lambda (metric relevance)
-          (match metric
-            ((field . weight)
-             (match (field obj)
-               (#f  relevance)
-               ((? string? str)
-                (+ relevance (* (score str) weight)))
-               ((lst ...)
-                (+ relevance (* weight (apply + (map score lst)))))))))
-        0
-        metrics))
+        (reduce + 0 scores))))
 
 (define %package-metrics
   ;; Metrics used to compute the "relevance score" of a package against a set