diff --git a/src/libostree/ostree-fetcher-curl.c b/src/libostree/ostree-fetcher-curl.c
index f66e6ae45f..14151811ba 100644
--- a/src/libostree/ostree-fetcher-curl.c
+++ b/src/libostree/ostree-fetcher-curl.c
@@ -386,6 +386,8 @@ update_timeout_cb (CURLM *multi, long timeout_ms, void *userp)
 {
   OstreeFetcher *fetcher = userp;
 
+  if (fetcher->timer_event)
+    g_source_destroy (fetcher->timer_event);
   fetcher->timer_event = g_timeout_source_new (timeout_ms);
   g_source_set_callback (fetcher->timer_event, timer_cb, fetcher, NULL);
   g_source_attach (fetcher->timer_event, fetcher->mainctx);