diff --git a/guix/remote.scm b/guix/remote.scm
index d49ee91b38..0959025963 100644
--- a/guix/remote.scm
+++ b/guix/remote.scm
@@ -102,7 +102,8 @@ (define sources
       (lowered-gexp-sources lowered))
 
     (if build-locally?
-        (let ((to-send (append (map derivation-input-output-paths inputs)
+        (let ((to-send (append (append-map derivation-input-output-paths
+                                           inputs)
                                sources)))
           (mbegin %store-monad
             (built-derivations inputs)