diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6d8584c53..05081fc6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved the style and wording of the position detail dialog
+- Improved the validation in the activities import (expects positive values for `fee`, `quantity` and `unitPrice`)
 - Changed the currency selector in the create or update account dialog to `@angular/material/autocomplete`
 - Upgraded `uuid` from version `9.0.0` to `9.0.1`
 - Upgraded `yahoo-finance2` from version `2.8.0` to `2.8.1`
diff --git a/apps/api/src/app/order/create-order.dto.ts b/apps/api/src/app/order/create-order.dto.ts
index 49b193ca5..3eafa704f 100644
--- a/apps/api/src/app/order/create-order.dto.ts
+++ b/apps/api/src/app/order/create-order.dto.ts
@@ -13,7 +13,9 @@ import {
   IsISO8601,
   IsNumber,
   IsOptional,
-  IsString
+  IsPositive,
+  IsString,
+  Min
 } from 'class-validator';
 import { isString } from 'lodash';
 
@@ -48,9 +50,11 @@ export class CreateOrderDto {
   date: string;
 
   @IsNumber()
+  @Min(0)
   fee: number;
 
   @IsNumber()
+  @IsPositive()
   quantity: number;
 
   @IsString()
@@ -64,6 +68,7 @@ export class CreateOrderDto {
   type: Type;
 
   @IsNumber()
+  @IsPositive()
   unitPrice: number;
 
   @IsBoolean()
diff --git a/apps/api/src/app/order/update-order.dto.ts b/apps/api/src/app/order/update-order.dto.ts
index a8c33c40e..9d968aa86 100644
--- a/apps/api/src/app/order/update-order.dto.ts
+++ b/apps/api/src/app/order/update-order.dto.ts
@@ -13,7 +13,9 @@ import {
   IsISO8601,
   IsNumber,
   IsOptional,
-  IsString
+  IsPositive,
+  IsString,
+  Min
 } from 'class-validator';
 import { isString } from 'lodash';
 
@@ -47,12 +49,14 @@ export class UpdateOrderDto {
   date: string;
 
   @IsNumber()
+  @Min(0)
   fee: number;
 
   @IsString()
   id: string;
 
   @IsNumber()
+  @IsPositive()
   quantity: number;
 
   @IsString()
@@ -66,5 +70,6 @@ export class UpdateOrderDto {
   type: Type;
 
   @IsNumber()
+  @IsPositive()
   unitPrice: number;
 }
diff --git a/apps/client/src/app/services/import-activities.service.ts b/apps/client/src/app/services/import-activities.service.ts
index 760871922..af7e8e6c9 100644
--- a/apps/client/src/app/services/import-activities.service.ts
+++ b/apps/client/src/app/services/import-activities.service.ts
@@ -286,7 +286,7 @@ export class ImportActivitiesService {
 
     for (const key of ImportActivitiesService.QUANTITY_KEYS) {
       if (isFinite(item[key])) {
-        return item[key];
+        return Math.abs(item[key]);
       }
     }
 
@@ -372,7 +372,7 @@ export class ImportActivitiesService {
 
     for (const key of ImportActivitiesService.UNIT_PRICE_KEYS) {
       if (isFinite(item[key])) {
-        return item[key];
+        return Math.abs(item[key]);
       }
     }