diff --git a/library/src/main/java/com/liulishuo/filedownloader/download/FetchDataTask.java b/library/src/main/java/com/liulishuo/filedownloader/download/FetchDataTask.java
index 2e69cf3f..69531d16 100644
--- a/library/src/main/java/com/liulishuo/filedownloader/download/FetchDataTask.java
+++ b/library/src/main/java/com/liulishuo/filedownloader/download/FetchDataTask.java
@@ -116,7 +116,8 @@ public void run() throws IOException, IllegalAccessException, IllegalArgumentExc
 
         try {
             final boolean isSupportSeek = CustomComponentHolder.getImpl().isSupportSeek();
-            if (hostRunnable != null && !isSupportSeek) {
+            final boolean isMultiConnection = connectionIndex >= 0;
+            if (isMultiConnection && !isSupportSeek) {
                 throw new IllegalAccessException(
                         "can't using multi-download when the output stream can't support seek");
             }