diff --git a/src/queries/catalog/monthly-cost-change-percentage.kql b/src/queries/catalog/monthly-cost-change-percentage.kql
index 0e36c8fbd..ea4664337 100644
--- a/src/queries/catalog/monthly-cost-change-percentage.kql
+++ b/src/queries/catalog/monthly-cost-change-percentage.kql
@@ -22,5 +22,5 @@ Costs()
 | extend PreviousBilledCost = prev(BilledCost)
 | extend PreviousEffectiveCost = prev(EffectiveCost)
 | project ChargePeriodStart,
-    BilledCostChangePct = iff(isempty(PreviousBilledCost), 0.0, toreal((BilledCost - PreviousBilledCost) * 100.0 / PreviousBilledCost)),
-    EffectiveCostChangePct = iff(isempty(PreviousEffectiveCost), 0.0, toreal((EffectiveCost - PreviousEffectiveCost) * 100.0 / PreviousEffectiveCost))
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+    BilledCostChangePct = iff(isempty(PreviousBilledCost) or PreviousBilledCost == 0.0, 0.0, toreal((BilledCost - PreviousBilledCost) * 100.0 / PreviousBilledCost)),
+    EffectiveCostChangePct = iff(isempty(PreviousEffectiveCost) or PreviousEffectiveCost == 0.0, 0.0, toreal((EffectiveCost - PreviousEffectiveCost) * 100.0 / PreviousEffectiveCost))
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