diff --git a/application/src/main/java/org/thingsboard/server/service/cf/ctx/state/aggregation/single/EntityAggregationCalculatedFieldState.java b/application/src/main/java/org/thingsboard/server/service/cf/ctx/state/aggregation/single/EntityAggregationCalculatedFieldState.java
index c945868576..f50bc602ce 100644
--- a/application/src/main/java/org/thingsboard/server/service/cf/ctx/state/aggregation/single/EntityAggregationCalculatedFieldState.java
+++ b/application/src/main/java/org/thingsboard/server/service/cf/ctx/state/aggregation/single/EntityAggregationCalculatedFieldState.java
@@ -293,7 +293,7 @@ public class EntityAggregationCalculatedFieldState extends BaseCalculatedFieldSt
                     Object resultValue = argumentEntry.getValue() instanceof Number number
                             ? NumberUtils.roundResult(number.doubleValue(), precision)
                             : argumentEntry.getValue();
-                    metricsNode.put(metricName, JacksonUtil.toString(resultValue));
+                    metricsNode.set(metricName, JacksonUtil.valueToTree(resultValue));
                 }
             }
             if (!metricsNode.isEmpty()) {