diff --git a/src/main/java/cc/blynk/clickhouse/http/DefaultHttpConnector.java b/src/main/java/cc/blynk/clickhouse/http/DefaultHttpConnector.java
index 7643b74..59efb71 100644
--- a/src/main/java/cc/blynk/clickhouse/http/DefaultHttpConnector.java
+++ b/src/main/java/cc/blynk/clickhouse/http/DefaultHttpConnector.java
@@ -190,7 +190,10 @@ private HttpURLConnection buildConnection(URI uri) throws ClickHouseException {
     }
 
     private void setDefaultHeaders(HttpURLConnection connection) {
-        connection.addRequestProperty("Authorization", properties.getHttpAuthorization());
+        String httpAuthorization = properties.getHttpAuthorization();
+        if (httpAuthorization != null) {
+            connection.addRequestProperty("Authorization", httpAuthorization);
+        }
         connection.addRequestProperty("Content-Type", "text/plain; charset=UTF-8");
     }