diff --git a/api/src/engine/models/result/line-chart-result.model.ts b/api/src/engine/models/result/line-chart-result.model.ts
index 594f564d3ad6ec0b9cfb99b01ecab7c479e21018..ccedd1c25186e6e60b138f55b38a2403a846a333 100644
--- a/api/src/engine/models/result/line-chart-result.model.ts
+++ b/api/src/engine/models/result/line-chart-result.model.ts
@@ -25,7 +25,7 @@ export class LineResult {
   @Field()
   label: string;
 
-  @Field(() => Number)
+  @Field(() => [Number])
   x: number[];
 
   @Field(() => [Number])