diff --git a/guix-data-service/web/render.scm b/guix-data-service/web/render.scm
index fee5daf..3e2cf79 100644
--- a/guix-data-service/web/render.scm
+++ b/guix-data-service/web/render.scm
@@ -169,11 +169,11 @@
         (if stream?
             (lambda (port)
               (setvbuf port 'block (expt 2 16))
-              (scm->json json port))
+              (scm->json json port #:unicode #t))
             (call-with-encoded-output-string
              "utf-8"
              (lambda (port)
-               (scm->json json port))))))
+               (scm->json json port #:unicode #t))))))
 
 (define* (render-text text #:key (extra-headers '())
                       (code 200))