diff --git a/lib/FastDownload.js b/lib/FastDownload.js
index 0971709..d8fe9d3 100755
--- a/lib/FastDownload.js
+++ b/lib/FastDownload.js
@@ -108,17 +108,17 @@ FastDownload.prototype._init_http = function (cb) {
     self._options.chunkSize = Math.ceil(self.size / self._options.chunksAtOnce)
   }
   var acceptRanges = self.headers['accept-ranges'] === 'bytes'
-  if (
-    !acceptRanges &&
-    (self._options.start !== 0 || self._options.end !== self.file_size)
-  ) {
-    cb(new Error('the server will not accept range requests'))
-    return
-  }
-  if (acceptRanges) {
-    self._init_fast_http(cb)
-  } else {
+  if (!acceptRanges) {
+    if (self._options.end.toString() != self.file_size.toString()) {
+      cb (new Error('the server will not accept range requests, so cannot change "end" of file'))
+    }
+
+    if (self._options.start !== 0) {
+      self._options.start = 0
+    }
     self._init_normal_http(cb)
+  } else {
+    self._init_fast_http(cb)
   }
 }
 FastDownload.prototype._init_normal_http = function (cb) {