diff --git a/ingester-protocol/src/main/java/io/greptime/BulkWriteClient.java b/ingester-protocol/src/main/java/io/greptime/BulkWriteClient.java
index 7386354..fc94aac 100644
--- a/ingester-protocol/src/main/java/io/greptime/BulkWriteClient.java
+++ b/ingester-protocol/src/main/java/io/greptime/BulkWriteClient.java
@@ -132,7 +132,7 @@ private BulkStreamWriter bulkStreamWriteTo(
         ctx.entrySet().forEach(e -> headers.insert(e.getKey(), String.valueOf(e.getValue())));
         headers.insert(Keys.Headers.GREPTIMEDB_DBNAME, database);
         if (authInfo != null) {
-            headers.insert(Keys.Headers.GREPTIMEDB_AUTH, authInfo.toBase64());
+            headers.insert(Keys.Headers.GREPTIMEDB_AUTH, authInfo.base64HeaderValue());
         }
         HeaderCallOption headerOption = new HeaderCallOption(headers);
         AsyncExecCallOption execOption = new AsyncExecCallOption(this.asyncPool);
diff --git a/ingester-protocol/src/main/java/io/greptime/models/AuthInfo.java b/ingester-protocol/src/main/java/io/greptime/models/AuthInfo.java
index f8ed5b4..b5ab035 100644
--- a/ingester-protocol/src/main/java/io/greptime/models/AuthInfo.java
+++ b/ingester-protocol/src/main/java/io/greptime/models/AuthInfo.java
@@ -54,9 +54,11 @@ public static AuthInfo noAuthorization() {
      *
      * @return the base64 encoded string
      */
-    public String toBase64() {
-        String authInfoStr = String.format("%s:%s", this.username, this.password);
-        return Base64.getEncoder().encodeToString(authInfoStr.getBytes(StandardCharsets.UTF_8));
+    public String base64HeaderValue() {
+        String encoded = Base64.getEncoder()
+                .encodeToString(
+                        String.format("%s:%s", this.username, this.password).getBytes(StandardCharsets.UTF_8));
+        return String.format("Basic %s", encoded);
     }
 
     @Override