diff --git a/src/octoprint/util/pip.py b/src/octoprint/util/pip.py
index 94b13926..7fa3dbc3 100644
--- a/src/octoprint/util/pip.py
+++ b/src/octoprint/util/pip.py
@@ -22,6 +22,7 @@ class PipCaller(object):
 		self._logger = logging.getLogger(__name__)
 
 		self.configured = configured
+		self.refresh = False
 
 		self._command = None
 		self._version = None