diff --git a/apps/enp/serializers.py b/apps/enp/serializers.py
index 50446648..2dc692fa 100644
--- a/apps/enp/serializers.py
+++ b/apps/enp/serializers.py
@@ -129,7 +129,8 @@ class EnvDataSerializer(CustomModelSerializer):
     def to_representation(self, instance):
         representation = super().to_representation(instance)
         for field_name in ("dust_rtd", "dust_zs", "temperature", "pressure", "speed", "humidity", "flux", "pm25", "pm10", "tsp", "wind_speed", "so2_rtd", "so2_zs", "nox_rtd", "nox_zs", "o2"):
-            representation[field_name] = round(representation[field_name], 4)
+            if representation[field_name]:
+                representation[field_name] = round(representation[field_name], 4)
         return representation