diff --git a/spec/index_writer/write_spec.rb b/spec/index_writer/write_spec.rb
index dbf151f..d8c393e 100644
--- a/spec/index_writer/write_spec.rb
+++ b/spec/index_writer/write_spec.rb
@@ -25,6 +25,14 @@ describe "IndexWriter#write" do
     File.exists?(@path + '/index.lock').should == false
   end
 
+  it "takes a higher number for the index file, if there is already one" do
+    FileUtils.touch @path + '/ind0.ind'
+    w = Polecat::IndexWriter.new @path
+    w.add Spec::FooDocument.new
+    w.write
+    File.exists?(@path + '/ind1.ind').should == true
+  end
+
   it "writes a marshalled representation of the document list" do
     w = Polecat::IndexWriter.new @path
     doc = Spec::FooDocument.new