diff --git a/octoprint_estop/__init__.py b/octoprint_estop/__init__.py
index b2c0664..e733fe1 100644
--- a/octoprint_estop/__init__.py
+++ b/octoprint_estop/__init__.py
@@ -45,6 +45,7 @@ class EstopPlugin(octoprint.plugin.StartupPlugin,
 		)
 
 __plugin_name__ = "Emergency Stop Button"
+__plugin_pythoncompat__ = ">=2.7,<4"
 
 def __plugin_load__():
 	global __plugin_implementation__