diff --git a/msd_pytorch/msd_model.py b/msd_pytorch/msd_model.py
index eaeac02..81440fb 100644
--- a/msd_pytorch/msd_model.py
+++ b/msd_pytorch/msd_model.py
@@ -191,6 +191,8 @@ def forward(self, input=None, target=None):
         if target is not None:
             self.set_target(target)
 
+        self.output = None
+        self.loss = None
         self.output = self.net(self.input)
         self.loss = self.criterion(self.output, self.target)