diff --git a/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java b/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
index 72ad6dc87..faa9daeee 100644
--- a/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
+++ b/other/java/client/src/main/java/seaweedfs/client/SeaweedOutputStream.java
@@ -118,6 +118,10 @@ public class SeaweedOutputStream extends OutputStream {
         int protoIndex = path.indexOf("://");
         if (protoIndex >= 0) {
             int pathStart = path.indexOf("/", protoIndex + 3);
+            if (pathStart < 0) {
+                // No path segment; treat as root (e.g., "seaweedfs://host")
+                return "/";
+            }
             path = path.substring(pathStart);
         }
         if (path.equals("/")) {