diff --git a/react-i18next/index.d.ts b/react-i18next/index.d.ts
index 85c8e8851c..41daf14c4a 100644
--- a/react-i18next/index.d.ts
+++ b/react-i18next/index.d.ts
@@ -39,7 +39,7 @@ interface InterpolateProps {
     useDangerouslySetInnerHTML?: boolean;
     dangerouslySetInnerHTMLPartElement?: string;
 
-    [regexKey: string]: InterpolateValue | RegExp | I18next.TranslationOptions | boolean;
+    [regexKey: string]: InterpolateValue | RegExp | I18next.TranslationOptions | boolean | undefined;
 }
 
 export class Interpolate extends React.Component<InterpolateProps, {}> { }
diff --git a/react-i18next/react-i18next-tests.tsx b/react-i18next/react-i18next-tests.tsx
index 012f920bc9..fa2e36fcb1 100644
--- a/react-i18next/react-i18next-tests.tsx
+++ b/react-i18next/react-i18next-tests.tsx
@@ -26,7 +26,7 @@ interface InnerAnotherComponentProps {
 
 class InnerAnotherComponent extends React.Component<InnerAnotherComponentProps, {}> {
     render() {
-        const { _ } = this.props;
+        const _ = this.props._!;
 
         return <p>{_('content.text', { /* options t options */ })}</p>;
     }
@@ -41,7 +41,7 @@ interface InnerYetAnotherComponentProps extends InjectedTranslateProps {
 
 class InnerYetAnotherComponent extends React.Component<InnerYetAnotherComponentProps, {}> {
     render() {
-        const { t } = this.props;
+        const t = this.props.t!;
 
         return <p>{t('usingDefaultNS', { /* options t options */ })}</p>;
     }
@@ -55,7 +55,7 @@ interface TranslatableViewProps extends InjectedTranslateProps {
 @translate(['view', 'nav'], { wait: true })
 class TranslatableView extends React.Component<TranslatableViewProps, {}> {
     render() {
-        const { t } = this.props;
+        const t = this.props.t!;
 
         let interpolateComponent = <strong>"a interpolated component"</strong>;
 
diff --git a/react-i18next/tsconfig.json b/react-i18next/tsconfig.json
index ba4f230166..b2109d366f 100644
--- a/react-i18next/tsconfig.json
+++ b/react-i18next/tsconfig.json
@@ -3,7 +3,7 @@
         "module": "commonjs",
         "target": "es6",
         "noImplicitAny": true,
-        "strictNullChecks": false,
+        "strictNullChecks": true,
         "baseUrl": "../",
         "typeRoots": [
             "../"