diff --git a/workspace_tools/export/__init__.py b/workspace_tools/export/__init__.py
index 72b866a781..ee26e2425d 100755
--- a/workspace_tools/export/__init__.py
+++ b/workspace_tools/export/__init__.py
@@ -85,7 +85,7 @@ def export(project_path, project_name, ide, target, destination='/tmp/',
     zip_path = None
     if report['success']:
         # add readme file to every offline export.
-        open(tempdir+"\\README.html",'w').write('<meta http-equiv="refresh" content="0; url=http://developer.mbed.org/handbook/ExportToOfflineToolchain#%s#%s"/>'% (target,ide))
+        open(os.path.join(temdir, 'README.html'),'w').write('<meta http-equiv="refresh" content="0; url=http://developer.mbed.org/handbook/ExportToOfflineToolchain#%s#%s"/>'% (target,ide))
         zip_path = zip_working_directory_and_clean_up(tempdir, destination, project_name, clean)
 
     return zip_path, report