diff --git a/homeassistant/components/sensor/filter.py b/homeassistant/components/sensor/filter.py
index f401da37aef..198630b02e7 100644
--- a/homeassistant/components/sensor/filter.py
+++ b/homeassistant/components/sensor/filter.py
@@ -232,7 +232,10 @@ class Filter(object):
         """Implement a common interface for filters."""
         filtered = self._filter_state(new_state)
         if self.precision is not None:
-            filtered = round(filtered, self.precision)
+            if self.precision < 1:
+                filtered = round(filtered / self.precision) * self.precision
+            else:
+                filtered = round(filtered, self.precision)
         self.states.append(filtered)
         return filtered