diff --git a/oni/home/services/unclutter.scm b/oni/home/services/unclutter.scm
index ba69d20..7794256 100644
--- a/oni/home/services/unclutter.scm
+++ b/oni/home/services/unclutter.scm
@@ -50,9 +50,9 @@
      #~(make-forkexec-constructor
         '#$(append
             (delete #f
-                    (list (file-append (home-unclutter-configuration-package config) "/bin/unclutter")
-                          "--timeout" (home-unclutter-configuration-timeout config)
-                          "--jitter" (home-unclutter-configuration-jitter config)
+                   (list (file-append (home-unclutter-configuration-package config) "/bin/unclutter")
+                          "--timeout" (number->string (home-unclutter-configuration-timeout config))
+                          "--jitter" (number->string (home-unclutter-configuration-jitter config))
                           (and (home-unclutter-configuration-exclude-root config) "--exclude-root")
                           (and (home-unclutter-configuration-ignore-scrolling config) "--ignore-scrolling")
                           (and (home-unclutter-configuration-hide-on-touch config) "--hide-on-touch")