diff --git a/Control/brewpi/mass.py b/Control/brewpi/mass.py
index fc8b8cd..353f601 100644
--- a/Control/brewpi/mass.py
+++ b/Control/brewpi/mass.py
@@ -26,6 +26,9 @@ class Mass(APlant):
 		if self.Td > 0:
 			self.alpha = self.dt/self.Td
 
+	def activate(self, enable):
+		pass
+
 	def process(self):
 		self.e = self.e*(1 - ((self.L*self.theta)*self.dt)/(self.M*self.C))
 		self.x = (1-self.alpha)*self.x + self.gain*self.alpha*self.P