diff --git a/gns3server/handlers/api/project_handler.py b/gns3server/handlers/api/project_handler.py
index ea9f4132..3c4a0fa2 100644
--- a/gns3server/handlers/api/project_handler.py
+++ b/gns3server/handlers/api/project_handler.py
@@ -361,8 +361,8 @@ class ProjectHandler:
 
         pm = ProjectManager.instance()
         project = pm.get_project(request.match_info["project_id"])
-        response.content_type = 'application/gns3z'
-        response.headers['CONTENT-DISPOSITION'] = 'attachment; filename="{}.gns3z"'.format(project.name)
+        response.content_type = 'application/gns3project'
+        response.headers['CONTENT-DISPOSITION'] = 'attachment; filename="{}.gns3project"'.format(project.name)
         response.enable_chunked_encoding()
         # Very important: do not send a content length otherwise QT close the connection but curl can consume the Feed
         response.content_length = None
diff --git a/tests/handlers/api/test_project.py b/tests/handlers/api/test_project.py
index cf952794..90a4a554 100644
--- a/tests/handlers/api/test_project.py
+++ b/tests/handlers/api/test_project.py
@@ -294,8 +294,8 @@ def test_export(server, tmpdir, loop, project):
 
     response = server.get("/projects/{project_id}/export".format(project_id=project.id), raw=True)
     assert response.status == 200
-    assert response.headers['CONTENT-TYPE'] == 'application/gns3z'
-    assert response.headers['CONTENT-DISPOSITION'] == 'attachment; filename="{}.gns3z"'.format(project.name)
+    assert response.headers['CONTENT-TYPE'] == 'application/gns3project'
+    assert response.headers['CONTENT-DISPOSITION'] == 'attachment; filename="{}.gns3project"'.format(project.name)
 
     with open(str(tmpdir / 'project.zip'), 'wb+') as f:
         f.write(response.body)