diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 4b10610281..fbb704bbb7 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -1669,7 +1669,7 @@ bool APIConnection::send_noise_encryption_set_key_response(const NoiseEncryption
     } else {
       ESP_LOGW(TAG, "Failed to clear encryption key");
     }
-  } else if (base64_decode(msg.key, psk.data(), msg.key.size()) != psk.size()) {
+  } else if (base64_decode(msg.key, psk.data(), psk.size()) != psk.size()) {
     ESP_LOGW(TAG, "Invalid encryption key length");
   } else if (!this->parent_->save_noise_psk(psk, true)) {
     ESP_LOGW(TAG, "Failed to save encryption key");