diff --git a/core/leras/layers/MsSsim.py b/core/leras/layers/MsSsim.py
index fff5f74..84028bb 100644
--- a/core/leras/layers/MsSsim.py
+++ b/core/leras/layers/MsSsim.py
@@ -19,7 +19,16 @@ class MsSsim(nn.LayerBase):
         # Transpose images from NCHW to NHWC
         y_true_t = tf.transpose(tf.cast(y_true, tf.float32), [0, 2, 3, 1])
         y_pred_t = tf.transpose(tf.cast(y_pred, tf.float32), [0, 2, 3, 1])
-        loss = tf.image.ssim_multiscale(y_true_t, y_pred_t, max_val, power_factors=self.power_factors)
-        return (1.0 - loss) / 2.0
+
+
+        def assign_device(op):
+            if op.type != 'Assert':
+                return '/gpu:0'
+            else:
+                return '/cpu:0'
+
+        with tf.device(assign_device):
+            loss = tf.image.ssim_multiscale(y_true_t, y_pred_t, max_val, power_factors=self.power_factors)
+            return (1.0 - loss) / 2.0
 
 nn.MsSsim = MsSsim