diff --git a/src/lib/gramjs/sessions/CallbackSession.js b/src/lib/gramjs/sessions/CallbackSession.js
index 8e5bc5635..d8add75c8 100644
--- a/src/lib/gramjs/sessions/CallbackSession.js
+++ b/src/lib/gramjs/sessions/CallbackSession.js
@@ -89,6 +89,8 @@ class CallbackSession extends MemorySession {
             .keys(this._authKeys)
             .forEach((dcId) => {
                 const authKey = this._authKeys[dcId];
+                if (!authKey._key) return;
+
                 sessionData.keys[dcId] = authKey._key.toString('hex');
                 sessionData.hashes[dcId] = authKey._hash.toString('hex');
             });
diff --git a/src/lib/gramjs/sessions/StorageSession.js b/src/lib/gramjs/sessions/StorageSession.js
index 306a3eb83..aef093638 100644
--- a/src/lib/gramjs/sessions/StorageSession.js
+++ b/src/lib/gramjs/sessions/StorageSession.js
@@ -110,6 +110,8 @@ class StorageSession extends MemorySession {
             .keys(this._authKeys)
             .forEach((dcId) => {
                 const authKey = this._authKeys[dcId];
+                if (!authKey._key) return;
+
                 sessionData.keys[dcId] = asHex ? authKey._key.toString('hex') : authKey._key;
                 sessionData.hashes[dcId] = asHex ? authKey._hash.toString('hex') : authKey._hash;
             });