diff --git a/guix-data-service/model/guix-revision.scm b/guix-data-service/model/guix-revision.scm
index 4dd4100..1cde5e2 100644
--- a/guix-data-service/model/guix-revision.scm
+++ b/guix-data-service/model/guix-revision.scm
@@ -30,10 +30,10 @@
             guix-revisions-cgit-url-bases))
 
 (define (count-guix-revisions conn)
-  (first
-   (exec-query
-    conn
-    "SELECT COUNT(*) FROM guix_revisions")))
+  (match (exec-query
+          conn
+          "SELECT COUNT(*) FROM guix_revisions")
+    (((x)) (string->number x))))
 
 (define (most-recent-n-guix-revisions conn n)
   (exec-query conn "SELECT * FROM guix_revisions ORDER BY id DESC LIMIT 10"))
diff --git a/guix-data-service/web/controller.scm b/guix-data-service/web/controller.scm
index a9a8a3e..863805f 100644
--- a/guix-data-service/web/controller.scm
+++ b/guix-data-service/web/controller.scm
@@ -348,10 +348,7 @@
                   (with-postgresql-connection
                    "web healthcheck"
                    (lambda (conn)
-                     (number?
-                      (string->number
-                       (first
-                        (count-guix-revisions conn)))))))
+                     (number? (count-guix-revisions conn)))))
                 (lambda (key . args)
                   #f))))
          (render-json