diff --git a/plugins/common/daemon-skeleton-gtk.h b/plugins/common/daemon-skeleton-gtk.h
index 0a24450..c19c138 100644
--- a/plugins/common/daemon-skeleton-gtk.h
+++ b/plugins/common/daemon-skeleton-gtk.h
@@ -161,6 +161,11 @@ register_with_cinnamon_session (void)
               NULL,
               (GAsyncReadyCallback) on_client_registered,
               NULL);
+
+   /* DESKTOP_AUTOSTART_ID must not leak into child processes, because
+    * it can't be reused. Child processes will not know whether this is
+    * a genuine value or erroneous already-used value. */
+   g_unsetenv ("DESKTOP_AUTOSTART_ID");
 }
 
 static gboolean
diff --git a/plugins/common/daemon-skeleton.h b/plugins/common/daemon-skeleton.h
index 1d86a65..08b519f 100644
--- a/plugins/common/daemon-skeleton.h
+++ b/plugins/common/daemon-skeleton.h
@@ -156,6 +156,11 @@ register_with_cinnamon_session (GMainLoop *loop)
               NULL,
               (GAsyncReadyCallback) on_client_registered,
               loop);
+
+   /* DESKTOP_AUTOSTART_ID must not leak into child processes, because
+    * it can't be reused. Child processes will not know whether this is
+    * a genuine value or erroneous already-used value. */
+   g_unsetenv ("DESKTOP_AUTOSTART_ID");
 }
 
 static gboolean