diff --git a/doc/guix.texi b/doc/guix.texi
index bbec1103c8..0d2a61347f 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -4385,7 +4385,7 @@ settings.
 
 @deffn {Monadic Procedure} guix-service [#:guix guix] @
        [#:builder-group "guixbuild"] [#:build-accounts 10] @
-       [#:authorize-hydra-key? #f] [#:use-substitutes? #t] @
+       [#:authorize-hydra-key? #t] [#:use-substitutes? #t] @
        [#:extra-options '()]
 Return a service that runs the build daemon from @var{guix}, and has
 @var{build-accounts} user accounts available under @var{builder-group}.
diff --git a/gnu/services/base.scm b/gnu/services/base.scm
index d55eb3a5f9..17dd0fb599 100644
--- a/gnu/services/base.scm
+++ b/gnu/services/base.scm
@@ -598,7 +598,7 @@ (define (hydra-key-authorization guix)
 failed to register hydra.gnu.org public key: ~a~%" status))))))))
 
 (define* (guix-service #:key (guix guix) (builder-group "guixbuild")
-                       (build-accounts 10) authorize-hydra-key?
+                       (build-accounts 10) (authorize-hydra-key? #t)
                        (use-substitutes? #t)
                        (extra-options '()))
   "Return a service that runs the build daemon from @var{guix}, and has