diff --git a/lib/osdb/movie_file.rb b/lib/osdb/movie_file.rb
index 17d4907..1570e87 100644
--- a/lib/osdb/movie_file.rb
+++ b/lib/osdb/movie_file.rb
@@ -22,7 +22,7 @@ def sub_path(format)
       else
         ".#{format}"
       end
-      path.gsub(File.extname(path), extension)
+      File.join(File.dirname(path), File.basename(path, File.extname(path)) + extension)
     end
     
     def hash
diff --git a/spec/osdb/movie_file_spec.rb b/spec/osdb/movie_file_spec.rb
index 8cdfe41..adf0374 100644
--- a/spec/osdb/movie_file_spec.rb
+++ b/spec/osdb/movie_file_spec.rb
@@ -9,4 +9,10 @@
   its(:hash) { should == '243339b48f4e8741' }
   its(:name) { should == 'somemovie' }
   
+  describe '#sub_path' do
+    it 'should only change the extension of the movie' do
+        movie_file = OSDb::MovieFile.new('directory-with-extension.avi/movie-file.avi', false)
+        movie_file.sub_path('srt').should == 'directory-with-extension.avi/movie-file.srt'
+    end
+  end
 end