diff --git a/guix-data-service/comparison.scm b/guix-data-service/comparison.scm
index 1559ac8..20945db 100644
--- a/guix-data-service/comparison.scm
+++ b/guix-data-service/comparison.scm
@@ -647,13 +647,20 @@ ORDER BY coalesce(base_packages.name, target_packages.name) ASC, base_packages.v
         ((pair)
          (cons pair result))))
     '()
-    (map (match-lambda
-           ((base-name base-version _ _ _ _ _ target-name target-version _ _ _ _ _)
-            (if (or (and (string? base-name) (string-null? base-name))
-                    (eq? base-name #f))
-                (cons target-name target-version)
-                (cons base-name base-version))))
-         package-data))))
+    (sort!
+     (map (match-lambda
+            ((base-name base-version _ _ _ _ _ target-name target-version _ _ _ _ _)
+             (if (or (and (string? base-name) (string-null? base-name))
+                     (eq? base-name #f))
+                 (cons target-name target-version)
+                 (cons base-name base-version))))
+          package-data)
+     (lambda (a b)
+       (let ((a-name (car a))
+             (b-name (car b)))
+         (if (string=? a-name b-name)
+             (string<? (cdr a) (cdr b))
+             (string<? a-name b-name))))))))
 
 (define (package-derivation-data-vhash->derivations conn packages-vhash)
   (define (vhash->derivation-ids vhash)