diff --git a/gnu/packages/gtk.scm b/gnu/packages/gtk.scm
index 8a0c7c5f6e..12132db50c 100644
--- a/gnu/packages/gtk.scm
+++ b/gnu/packages/gtk.scm
@@ -328,7 +328,11 @@ (define-public libthai
                        "/share/doc/libthai/html"))))
     (native-inputs
      `(("doxygen" ,doxygen)
-       ("pkg-config" ,pkg-config)))
+       ("pkg-config" ,pkg-config)
+       ;; TODO(core-updates): Make this input unconditional.
+       ,@(if (%current-target-system)
+             `(("datrie" ,libdatrie)) ; for 'trietool'
+             '())))
     (propagated-inputs
      `(("datrie" ,libdatrie)))
     (synopsis "Thai language support library")