diff --git a/firmware/protect.c b/firmware/protect.c
index 3b586e5..ffbe4aa 100644
--- a/firmware/protect.c
+++ b/firmware/protect.c
@@ -257,7 +257,7 @@ bool protectPassphrase(void)
 		if (msg_tiny_id == MessageType_MessageType_PassphraseAck) {
 			msg_tiny_id = 0xFFFF;
 			PassphraseAck *ppa = (PassphraseAck *)msg_tiny;
-			session_cachePassphrase(ppa->passphrase);
+			session_cachePassphrase(ppa->has_passphrase ? ppa->passphrase : "");
 			result = true;
 			break;
 		}
diff --git a/vendor/trezor-common b/vendor/trezor-common
index 43b6464..d85f7ac 160000
--- a/vendor/trezor-common
+++ b/vendor/trezor-common
@@ -1 +1 @@
-Subproject commit 43b64648832028efbb93079a1bd17794ed4044cb
+Subproject commit d85f7ac6bbcccbc83012d85fdf25635e57c5f15b