diff --git a/guix/ui.scm b/guix/ui.scm
index ae727eb837..b65702474d 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -550,19 +550,24 @@ interpreted."
                                    (manifest-entry-version parent))
                      (report-parent-entries parent))))
 
+               (define (manifest-entry-output* entry)
+                 (match (manifest-entry-output entry)
+                   ("out"   "")
+                   (output (string-append ":" output))))
+
                (report-error (G_ "profile contains conflicting entries for ~a:~a~%")
                              (manifest-entry-name entry)
                              (manifest-entry-output entry))
-               (report-error (G_ "  first entry: ~a@~a:~a ~a~%")
+               (report-error (G_ "  first entry: ~a@~a~a ~a~%")
                              (manifest-entry-name entry)
                              (manifest-entry-version entry)
-                             (manifest-entry-output entry)
+                             (manifest-entry-output* entry)
                              (manifest-entry-item entry))
                (report-parent-entries entry)
-               (report-error (G_ "  second entry: ~a@~a:~a ~a~%")
+               (report-error (G_ "  second entry: ~a@~a~a ~a~%")
                              (manifest-entry-name conflict)
                              (manifest-entry-version conflict)
-                             (manifest-entry-output conflict)
+                             (manifest-entry-output* conflict)
                              (manifest-entry-item conflict))
                (report-parent-entries conflict)
                (exit 1)))