diff --git a/src/model.py b/src/model.py
index 230b83cc2..4b9266279 100644
--- a/src/model.py
+++ b/src/model.py
@@ -32,8 +32,9 @@ def norm(x, scope, *, axis=-1, epsilon=1e-5):
         g = tf.get_variable('g', [n_state], initializer=tf.constant_initializer(1))
         b = tf.get_variable('b', [n_state], initializer=tf.constant_initializer(0))
         u = tf.reduce_mean(x, axis=axis, keepdims=True)
-        s = tf.reduce_mean(tf.square(x-u), axis=axis, keepdims=True)
-        x = (x - u) * tf.rsqrt(s + epsilon)
+        n = x-u
+        s = tf.reduce_mean(tf.square(n), axis=axis, keepdims=True)
+        x = n * tf.rsqrt(s + epsilon)
         x = x*g + b
         return x