1 files changed, 1 insertions, 0 deletions

diff --git a/src/util/mq.c b/src/util/mq.c
index d2f5add19..72ab8b72d 100644
--- a/src/util/mq.c
+++ b/src/util/mq.c
@@ -964,6 +964,7 @@ GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
   {
     /* complex case, we already started with transmitting
        the message using the callbacks. */
+    GNUNET_assert (GNUNET_NO == mq->in_flight);
     GNUNET_assert (0 < mq->queue_length);
     mq->queue_length--;
     mq->cancel_impl (mq,