diff --git a/drivers/net/wireless/ath/ath9k/rng.c b/drivers/net/wireless/ath/ath9k/rng.c
index 568b1c6c2b2b9fafcd4ee4521856285b1665b868..73f46fb3e83a14ff9f867c81aff4183ccdaacb03 100644
--- a/drivers/net/wireless/ath/ath9k/rng.c
+++ b/drivers/net/wireless/ath/ath9k/rng.c
@@ -120,6 +120,8 @@ void ath9k_rng_start(struct ath_softc *sc)
 
 void ath9k_rng_stop(struct ath_softc *sc)
 {
-	if (sc->rng_task)
+	if (sc->rng_task) {
 		kthread_stop(sc->rng_task);
+		sc->rng_task = NULL;
+	}
 }