diff --git a/guix/download.scm b/guix/download.scm
index 2d4bf749518ac566de0973e75e0a7b7392c347a7..4f16c3a900eec75bb2fb834c3f380e9e179629f1 100644
--- a/guix/download.scm
+++ b/guix/download.scm
@@ -258,7 +258,11 @@ (define builder
                             #:guile-for-build guile-for-build
 
                             ;; In general, offloading downloads is not a good idea.
-                            #:local-build? #t)
+                            ;;#:local-build? #t
+                            ;; FIXME: The above would also disable use of
+                            ;; substitutes, so comment it out; see
+                            ;; <https://bugs.gnu.org/18747>.
+                            )
           #:guile-for-build guile-for-build
           #:system system))))
 
diff --git a/guix/git-download.scm b/guix/git-download.scm
index b88339bed3e6de46b9f115004d99aa44f7f7151a..94b118a7b9a67ed173dfbb8d609da59be3eaf3ef 100644
--- a/guix/git-download.scm
+++ b/guix/git-download.scm
@@ -98,7 +98,8 @@ (define build
   (run-with-store store
     (gexp->derivation (or name "git-checkout") build
                       #:system system
-                      #:local-build? #t
+                      ;; FIXME: See <https://bugs.gnu.org/18747>.
+                      ;;#:local-build? #t
                       #:hash-algo hash-algo
                       #:hash hash
                       #:recursive? #t
diff --git a/guix/svn-download.scm b/guix/svn-download.scm
index 31dd1a90e83ebf7730ce63d6ec2d78a3da814e11..f06e44977770b632e4aef36afd74fa897d92db33 100644
--- a/guix/svn-download.scm
+++ b/guix/svn-download.scm
@@ -76,7 +76,8 @@ (define build
   (run-with-store store
     (gexp->derivation (or name "svn-checkout") build
                       #:system system
-                      #:local-build? #t
+                      ;; FIXME: See <https://bugs.gnu.org/18747>.
+                      ;;#:local-build? #t
                       #:hash-algo hash-algo
                       #:hash hash
                       #:recursive? #t