diff --git a/architectures/tensorflow_components/shared_variables.py b/architectures/tensorflow_components/shared_variables.py
index 8ee623e..2775251 100644
--- a/architectures/tensorflow_components/shared_variables.py
+++ b/architectures/tensorflow_components/shared_variables.py
@@ -40,8 +40,9 @@ class SharedRunningStats(object):
                     name="count", trainable=False)
 
                 self._shape = shape
-                self._mean = tf.to_float(self._sum / self._count)
-                self._std = tf.sqrt(tf.maximum(tf.to_float(self._sum_squared / self._count) - tf.square(self._mean), 1e-2))
+                self._mean = self._sum / self._count
+                self._std = tf.sqrt(tf.maximum((self._sum_squared - self._count*tf.square(self._mean))
+                                               / tf.maximum(self._count-1, 1), epsilon))
 
                 self.new_sum = tf.placeholder(shape=self.shape, dtype=tf.float64, name='sum')
                 self.new_sum_squared = tf.placeholder(shape=self.shape, dtype=tf.float64, name='var')