diff --git a/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts b/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
index f847c3c037..124346812f 100644
--- a/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
+++ b/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
@@ -928,7 +928,7 @@ export abstract class PortfolioCalculator {
   }: {
     activities: PortfolioCalculatorActivityItem[];
     exchangeRates: { [dateString: string]: number };
-    unitPriceAtStartDate: Big;
+    unitPriceAtStartDate: Big | undefined;
   }): HoldingValuation {
     const currentExchangeRate = exchangeRates[format(new Date(), DATE_FORMAT)];
     const currentValues: { [date: string]: Big } = {};
diff --git a/apps/api/src/app/portfolio/interfaces/holding-valuation-item.interface.ts b/apps/api/src/app/portfolio/interfaces/holding-valuation-item.interface.ts
index 439e219c72..9a5ff4fcd2 100644
--- a/apps/api/src/app/portfolio/interfaces/holding-valuation-item.interface.ts
+++ b/apps/api/src/app/portfolio/interfaces/holding-valuation-item.interface.ts
@@ -1,7 +1,7 @@
-import { PortfolioCalculatorActivityItem } from '@ghostfolio/api/app/portfolio/interfaces/portfolio-calculator-activity-item.interface';
-
 import { Big } from 'big.js';
 
+import { PortfolioCalculatorActivityItem } from './portfolio-calculator-activity-item.interface';
+
 export interface HoldingValuationItem extends Pick<
   PortfolioCalculatorActivityItem,
   'date' | 'itemType' | 'type'
diff --git a/apps/api/src/app/portfolio/interfaces/holding-valuation.interface.ts b/apps/api/src/app/portfolio/interfaces/holding-valuation.interface.ts
index 0c46ccd1c4..9e13fb70b4 100644
--- a/apps/api/src/app/portfolio/interfaces/holding-valuation.interface.ts
+++ b/apps/api/src/app/portfolio/interfaces/holding-valuation.interface.ts
@@ -1,7 +1,7 @@
-import { HoldingValuationItem } from '@ghostfolio/api/app/portfolio/interfaces/holding-valuation-item.interface';
-
 import { Big } from 'big.js';
 
+import { HoldingValuationItem } from './holding-valuation-item.interface';
+
 export interface HoldingValuation {
   currentValues: { [date: string]: Big };
   currentValuesWithCurrencyEffect: { [date: string]: Big };