diff --git a/packages/lib/src/components/ClickToPay/ClickToPay.tsx b/packages/lib/src/components/ClickToPay/ClickToPay.tsx
index 395665fd95..f26e64e6d1 100644
--- a/packages/lib/src/components/ClickToPay/ClickToPay.tsx
+++ b/packages/lib/src/components/ClickToPay/ClickToPay.tsx
@@ -15,8 +15,8 @@ import { TxVariants } from '../tx-variants';
 export class ClickToPayElement extends UIElement<ClickToPayElementProps> {
     public static type = TxVariants.clicktopay;
 
-    private clickToPayService: IClickToPayService | null;
-    private ctpConfiguration: ClickToPayConfiguration;
+    private readonly clickToPayService: IClickToPayService | null;
+    private readonly ctpConfiguration: ClickToPayConfiguration;
 
     constructor(props: ClickToPayElementProps) {
         super(props);
diff --git a/packages/lib/src/components/Donation/Donation.tsx b/packages/lib/src/components/Donation/Donation.tsx
index 478e94afa1..ad7234ca91 100644
--- a/packages/lib/src/components/Donation/Donation.tsx
+++ b/packages/lib/src/components/Donation/Donation.tsx
@@ -15,7 +15,7 @@ interface DonationProps extends UIElementProps {
 class DonationElement extends UIElement<DonationProps> {
     public static type = TxVariants.donation;
 
-    constructor(props) {
+    constructor(props: DonationProps) {
         super(props);
         this.donate = this.donate.bind(this);
     }
diff --git a/packages/lib/src/components/Giftcard/Giftcard.tsx b/packages/lib/src/components/Giftcard/Giftcard.tsx
index ef77264bab..d814fc135a 100644
--- a/packages/lib/src/components/Giftcard/Giftcard.tsx
+++ b/packages/lib/src/components/Giftcard/Giftcard.tsx
@@ -5,20 +5,10 @@ import CoreProvider from '../../core/Context/CoreProvider';
 import PayButton from '../internal/PayButton';
 import AdyenCheckoutError from '../../core/Errors/AdyenCheckoutError';
 import { PaymentAmount } from '../../types';
-import { PaymentResponse, UIElementProps } from '../types';
-import { GiftCardElementData } from './types';
+import { PaymentResponse } from '../types';
+import { GiftCardElementData, GiftCardProps } from './types';
 import { TxVariants } from '../tx-variants';
 
-// TODO: Fix these types
-interface GiftCardProps extends UIElementProps {
-    brandsConfiguration?: any;
-    brand?: string;
-    onOrderCreated?(data): void;
-    onOrderRequest?(resolve, reject, data): void;
-    onBalanceCheck?(resolve, reject, data): void;
-    onRequiringConfirmation?(): void;
-}
-
 export class GiftcardElement extends UIElement<GiftCardProps> {
     public static type = TxVariants.giftcard;
 
diff --git a/packages/lib/src/components/Giftcard/types.ts b/packages/lib/src/components/Giftcard/types.ts
index efa783e9e1..182ce5b2b5 100644
--- a/packages/lib/src/components/Giftcard/types.ts
+++ b/packages/lib/src/components/Giftcard/types.ts
@@ -1,3 +1,7 @@
+import { UIElementProps } from '../types';
+import { FunctionComponent } from 'preact';
+import { GiftcardFieldsProps } from './components/types';
+
 export interface GiftCardElementData {
     paymentMethod: {
         type: 'giftcard';
@@ -6,3 +10,19 @@ export interface GiftCardElementData {
         encryptedSecurityCode: string;
     };
 }
+
+// TODO: Fix these types
+export interface GiftCardProps extends UIElementProps {
+    pinRequired?: boolean;
+    expiryDateRequired?: boolean;
+    brandsConfiguration?: any;
+    brand?: string;
+    onOrderCreated?(data): void;
+    onOrderRequest?(resolve, reject, data): void;
+    onBalanceCheck?(resolve, reject, data): void;
+    onRequiringConfirmation?(): void;
+    /**
+     * @internal
+     */
+    fieldsLayoutComponent?: FunctionComponent<GiftcardFieldsProps>;
+}
diff --git a/packages/lib/src/components/MealVoucherFR/MealVoucherFR.tsx b/packages/lib/src/components/MealVoucherFR/MealVoucherFR.tsx
index 140627e55a..467f6f1b85 100644
--- a/packages/lib/src/components/MealVoucherFR/MealVoucherFR.tsx
+++ b/packages/lib/src/components/MealVoucherFR/MealVoucherFR.tsx
@@ -1,6 +1,7 @@
 import GiftcardElement from '../Giftcard/Giftcard';
 import { MealVoucherFields } from './components/MealVoucherFields';
 import { TxVariants } from '../tx-variants';
+import { GiftCardProps } from '../Giftcard/types';
 
 export class MealVoucherFRElement extends GiftcardElement {
     public static type = TxVariants.mealVoucher_FR;
@@ -11,7 +12,7 @@ export class MealVoucherFRElement extends GiftcardElement {
         TxVariants.mealVoucher_FR_groupeup
     ];
 
-    constructor(props) {
+    constructor(props: GiftCardProps) {
         super({
             ...props,
             pinRequired: true,
diff --git a/packages/lib/src/components/OnlinebankingPL/OnlineBankingPL.tsx b/packages/lib/src/components/OnlinebankingPL/OnlineBankingPL.tsx
index 1871ff9a0e..627408d1ee 100644
--- a/packages/lib/src/components/OnlinebankingPL/OnlineBankingPL.tsx
+++ b/packages/lib/src/components/OnlinebankingPL/OnlineBankingPL.tsx
@@ -1,4 +1,4 @@
-import IssuerListContainer from '../helpers/IssuerListContainer';
+import IssuerListContainer, { IssuerListContainerProps } from '../helpers/IssuerListContainer';
 import { TxVariants } from '../tx-variants';
 
 class OnlineBankingPL extends IssuerListContainer {
@@ -14,7 +14,7 @@ class OnlineBankingPL extends IssuerListContainer {
         urls: [OnlineBankingPL.disclaimerUrlsMap.regulation, OnlineBankingPL.disclaimerUrlsMap.obligation]
     };
 
-    constructor(props?) {
+    constructor(props: IssuerListContainerProps) {
         super({ ...props, termsAndConditions: OnlineBankingPL.termsAndConditions });
     }
 }
diff --git a/packages/lib/src/components/UIElement.tsx b/packages/lib/src/components/UIElement.tsx
index d06f870a50..96c3556f20 100644
--- a/packages/lib/src/components/UIElement.tsx
+++ b/packages/lib/src/components/UIElement.tsx
@@ -27,7 +27,7 @@ export abstract class UIElement<P extends UIElementProps = UIElementProps> exten
      */
     public static txVariants: string[] = [];
 
-    constructor(props?: P) {
+    constructor(props: P) {
         super(props);
 
         // Only register UIElements that have the 'type' set. Drop-in for example does not have.
diff --git a/packages/lib/src/components/helpers/IssuerListContainer.tsx b/packages/lib/src/components/helpers/IssuerListContainer.tsx
index cd84d6d0c3..05fd1dd39b 100644
--- a/packages/lib/src/components/helpers/IssuerListContainer.tsx
+++ b/packages/lib/src/components/helpers/IssuerListContainer.tsx
@@ -36,7 +36,7 @@ class IssuerListContainer extends UIElement<IssuerListContainerProps> {
         showPaymentMethodItemImages: false
     };
 
-    constructor(props?: IssuerListContainerProps) {
+    constructor(props: IssuerListContainerProps) {
         super(props);
 
         const getImage = props => this.resources.getImage(props);
@@ -62,7 +62,7 @@ class IssuerListContainer extends UIElement<IssuerListContainerProps> {
     formatData(): IssuerListData {
         return {
             paymentMethod: {
-                type: this.constructor['type'],
+                type: this.type,
                 issuer: this.state?.data?.issuer
             }
         };
diff --git a/yarn.lock b/yarn.lock
index 0cdb148bfd..9234f304b4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -12317,7 +12317,7 @@ regenerate@^1.4.2:
   resolved "https://registry.yarnpkg.com/regenerate/-/regenerate-1.4.2.tgz#b9346d8827e8f5a32f7ba29637d398b69014848a"
   integrity sha512-zrceR/XhGYU/d/opr2EKO7aRHUeiBI8qjtfHqADTwZd6Szfy16la6kqD0MIUs5z5hx6AaKa+PixpPrR289+I0A==
 
-regenerator-runtime@^0.13.11:
+regenerator-runtime@^0.13.11, regenerator-runtime@^0.13.9:
   version "0.13.11"
   resolved "https://registry.yarnpkg.com/regenerator-runtime/-/regenerator-runtime-0.13.11.tgz#f6dca3e7ceec20590d07ada785636a90cdca17f9"
   integrity sha512-kY1AZVr2Ra+t+piVaJ4gxaFaReZVH40AKNo7UCX6W+dEwBo/2oZJzqfuN1qLq1oL45o56cPaTXELwrTh8Fpggg==