diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index 1ad48dd79..65f5ce5f2 100644
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -753,7 +753,7 @@ struct wpa_driver_ops {
 	 * @seq: sequence number/packet number, seq_len octets, the next
 	 *	packet number to be used for in replay protection; configured
 	 *	for Rx keys (in most cases, this is only used with broadcast
-	 *	keys and set to zero for unicast keys)
+	 *	keys and set to zero for unicast keys); %NULL if not set
 	 * @seq_len: length of the seq, depends on the algorithm:
 	 *	TKIP: 6 octets, CCMP: 6 octets, IGTK: 6 octets
 	 * @key: key buffer; TKIP: 16-byte temporal key, 8-byte Tx Mic key,
diff --git a/src/drivers/driver_atmel.c b/src/drivers/driver_atmel.c
index cbec6c38d..8d748d386 100644
--- a/src/drivers/driver_atmel.c
+++ b/src/drivers/driver_atmel.c
@@ -248,7 +248,8 @@ static int wpa_driver_atmel_set_key(const char *ifname, void *priv,
         param->alg = alg_type;
         param->key_idx = key_idx;
         param->set_tx = set_tx;
-        os_memcpy(param->seq, seq, seq_len);
+	if (seq)
+		os_memcpy(param->seq, seq, seq_len);
         param->seq_len = seq_len;
         param->key_len = key_len;
 	os_memcpy((u8 *)param->key, key, key_len);
diff --git a/src/drivers/driver_bsd.c b/src/drivers/driver_bsd.c
index 6067dc391..c9520ec1a 100644
--- a/src/drivers/driver_bsd.c
+++ b/src/drivers/driver_bsd.c
@@ -347,7 +347,8 @@ bsd_set_key(const char *ifname, void *priv, enum wpa_alg alg,
 	if (wk.ik_keyix != IEEE80211_KEYIX_NONE && set_tx)
 		wk.ik_flags |= IEEE80211_KEY_DEFAULT;
 	wk.ik_keylen = key_len;
-	os_memcpy(&wk.ik_keyrsc, seq, seq_len);
+	if (seq)
+		os_memcpy(&wk.ik_keyrsc, seq, seq_len);
 	os_memcpy(wk.ik_keydata, key, key_len);
 
 	return set80211var(priv, IEEE80211_IOC_WPAKEY, &wk, sizeof(wk));
diff --git a/src/drivers/driver_hostap.c b/src/drivers/driver_hostap.c
index e47983cb7..624293b76 100644
--- a/src/drivers/driver_hostap.c
+++ b/src/drivers/driver_hostap.c
@@ -1307,7 +1307,8 @@ static int wpa_driver_hostap_set_key(const char *ifname, void *priv,
 		   HOSTAP_CRYPT_ALG_NAME_LEN);
 	param->u.crypt.flags = set_tx ? HOSTAP_CRYPT_FLAG_SET_TX_KEY : 0;
 	param->u.crypt.idx = key_idx;
-	os_memcpy(param->u.crypt.seq, seq, seq_len);
+	if (seq)
+		os_memcpy(param->u.crypt.seq, seq, seq_len);
 	param->u.crypt.key_len = key_len;
 	os_memcpy((u8 *) (param + 1), key, key_len);
 
diff --git a/src/drivers/driver_ipw.c b/src/drivers/driver_ipw.c
index 77984f9e5..d6c8f2939 100644
--- a/src/drivers/driver_ipw.c
+++ b/src/drivers/driver_ipw.c
@@ -264,7 +264,8 @@ static int wpa_driver_ipw_set_key(const char *ifname, void *priv,
 		   IPW_CRYPT_ALG_NAME_LEN);
 	param->u.crypt.set_tx = set_tx ? 1 : 0;
 	param->u.crypt.idx = key_idx;
-	os_memcpy(param->u.crypt.seq, seq, seq_len);
+	if (seq)
+		os_memcpy(param->u.crypt.seq, seq, seq_len);
 	param->u.crypt.key_len = key_len;
 	os_memcpy((u8 *) (param + 1), key, key_len);
 
diff --git a/src/drivers/driver_madwifi.c b/src/drivers/driver_madwifi.c
index ebbdfeb3b..570fc4c96 100644
--- a/src/drivers/driver_madwifi.c
+++ b/src/drivers/driver_madwifi.c
@@ -1511,7 +1511,7 @@ wpa_driver_madwifi_set_key(const char *ifname, void *priv, enum wpa_alg alg,
 	wk.ik_keyix = key_idx;
 	wk.ik_keylen = key_len;
 #ifdef WORDS_BIGENDIAN
-	{
+	if (seq) {
 		size_t i;
 		u8 tmp[WPA_KEY_RSC_LEN];
 		os_memset(tmp, 0, sizeof(tmp));
@@ -1520,7 +1520,8 @@ wpa_driver_madwifi_set_key(const char *ifname, void *priv, enum wpa_alg alg,
 		os_memcpy(&wk.ik_keyrsc, tmp, WPA_KEY_RSC_LEN);
 	}
 #else /* WORDS_BIGENDIAN */
-	os_memcpy(&wk.ik_keyrsc, seq, seq_len);
+	if (seq)
+		os_memcpy(&wk.ik_keyrsc, seq, seq_len);
 #endif /* WORDS_BIGENDIAN */
 	os_memcpy(wk.ik_keydata, key, key_len);
 
diff --git a/src/drivers/driver_ndiswrapper.c b/src/drivers/driver_ndiswrapper.c
index cd2f61e46..3abdb6442 100644
--- a/src/drivers/driver_ndiswrapper.c
+++ b/src/drivers/driver_ndiswrapper.c
@@ -128,7 +128,7 @@ static int wpa_ndiswrapper_set_key(const char *ifname, void *priv,
 	wpa_key.addr = addr;
 	wpa_key.key_index = key_idx;
 	wpa_key.set_tx = set_tx;
-	wpa_key.seq = seq;
+	wpa_key.seq = seq ? seq : (u8 *) "";
 	wpa_key.seq_len = seq_len;
 	wpa_key.key = key;
 	wpa_key.key_len = key_len;
diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index 6658e5355..18bb39580 100644
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -134,7 +134,7 @@ int wpa_set_wep_keys(struct wpa_supplicant *wpa_s, struct wpa_ssid *ssid)
 		set = 1;
 		wpa_drv_set_key(wpa_s, WPA_ALG_WEP,
 				(u8 *) "\xff\xff\xff\xff\xff\xff",
-				i, i == ssid->wep_tx_keyidx, (u8 *) "", 0,
+				i, i == ssid->wep_tx_keyidx, NULL, 0,
 				ssid->wep_key[i], ssid->wep_key_len[i]);
 	}
 
diff --git a/wpa_supplicant/wpas_glue.c b/wpa_supplicant/wpas_glue.c
index 4af0cd032..607f44b0f 100644
--- a/wpa_supplicant/wpas_glue.c
+++ b/wpa_supplicant/wpas_glue.c
@@ -212,7 +212,7 @@ static int wpa_eapol_set_wep_key(void *ctx, int unicast, int keyidx,
 	return wpa_drv_set_key(wpa_s, WPA_ALG_WEP,
 			       unicast ? wpa_s->bssid :
 			       (u8 *) "\xff\xff\xff\xff\xff\xff",
-			       keyidx, unicast, (u8 *) "", 0, key, keylen);
+			       keyidx, unicast, NULL, 0, key, keylen);
 }