diff --git a/backend/classes/ConfigFile.ts b/backend/classes/ConfigFile.ts
index 88ada62..2b3558c 100644
--- a/backend/classes/ConfigFile.ts
+++ b/backend/classes/ConfigFile.ts
@@ -125,7 +125,7 @@ export default class {
 			typeof data.OffsetWatts === 'number' &&
 			typeof data.BatteryCapacity === 'number' &&
 			typeof data.CarEfficiency === 'number' &&
-			typeof data.PreferredPhase === 'string'
+			typeof data.PreferredPhase === 'number'
 		);
 	}
 }