diff --git a/src/panels/lovelace/cards/energy/hui-energy-usage-graph-card.ts b/src/panels/lovelace/cards/energy/hui-energy-usage-graph-card.ts
index 354e14c993..bc807a2e04 100644
--- a/src/panels/lovelace/cards/energy/hui-energy-usage-graph-card.ts
+++ b/src/panels/lovelace/cards/energy/hui-energy-usage-graph-card.ts
@@ -386,7 +386,7 @@ export class HuiEnergyUsageGraphCard
           if (stat.sum === null) {
             return;
           }
-          if (!prevValue) {
+          if (prevValue === undefined) {
             prevValue = stat.sum;
             return;
           }