diff --git a/src/liblsquic/lsquic_send_ctl.c b/src/liblsquic/lsquic_send_ctl.c
index 27adb02..3800e3e 100644
--- a/src/liblsquic/lsquic_send_ctl.c
+++ b/src/liblsquic/lsquic_send_ctl.c
@@ -3205,6 +3205,10 @@ send_ctl_resize_q (struct lsquic_send_ctl *ctl, struct lsquic_packets_tailq *q,
     unsigned count_src = 0, count_dst = 0;
     int idx;
 
+#ifdef MSVC
+    idx = 0;
+#endif
+
     /* Initialize input, removing packets from source queue, filtering by path.
      * Note: this may reorder packets from different paths.
      */