diff --git a/extensions/php/src/features/completionItemProvider.ts b/extensions/php/src/features/completionItemProvider.ts
index 3d918dc4cf58953daccfcd1a435da6b67ebe037a..05a0f9f29bcba88ad24aaeca95f1ba6058a80ee5 100644
--- a/extensions/php/src/features/completionItemProvider.ts
+++ b/extensions/php/src/features/completionItemProvider.ts
@@ -12,7 +12,7 @@ export default class PHPCompletionItemProvider implements CompletionItemProvider
 
 	public triggerCharacters = ['.', ':', '$'];
 
-	public provideCompletionItems(document: TextDocument, position: Position, token: CancellationToken): Promise<CompletionItem[]> {
+	public provideCompletionItems(document: TextDocument, position: Position, _token: CancellationToken): Promise<CompletionItem[]> {
 		let result: CompletionItem[] = [];
 
 		let shouldProvideCompletionItems = workspace.getConfiguration('php').get<boolean>('suggest.basic', true);
diff --git a/extensions/php/src/features/hoverProvider.ts b/extensions/php/src/features/hoverProvider.ts
index 2e0a137ec0ab4dbcc765c281b1037f4869042bda..f40d210b13339a1d10c2235a29965d54a177a06a 100644
--- a/extensions/php/src/features/hoverProvider.ts
+++ b/extensions/php/src/features/hoverProvider.ts
@@ -11,15 +11,15 @@ import { textToMarkedString } from './utils/markedTextUtil';
 
 export default class PHPHoverProvider implements HoverProvider {
 
-	public provideHover(document: TextDocument, position: Position, token: CancellationToken): Hover | undefined {
+	public provideHover(document: TextDocument, position: Position, _token: CancellationToken): Hover | undefined {
 		let enable = workspace.getConfiguration('php').get<boolean>('suggest.basic', true);
 		if (!enable) {
-			return;
+			return undefined;
 		}
 
 		let wordRange = document.getWordRangeAtPosition(position);
 		if (!wordRange) {
-			return;
+			return undefined;
 		}
 
 		let name = document.getText(wordRange);
@@ -30,5 +30,7 @@ export default class PHPHoverProvider implements HoverProvider {
 			let contents: MarkedString[] = [textToMarkedString(entry.description), { language: 'php', value: signature }];
 			return new Hover(contents, wordRange);
 		}
+
+		return undefined;
 	}
 }
diff --git a/extensions/php/src/features/signatureHelpProvider.ts b/extensions/php/src/features/signatureHelpProvider.ts
index 42c14b8066aab60f029f3e89b56ec28ebd935d1d..b3f6c12a306a5cff443f3d4db54be6bcfbecbdad 100644
--- a/extensions/php/src/features/signatureHelpProvider.ts
+++ b/extensions/php/src/features/signatureHelpProvider.ts
@@ -69,7 +69,7 @@ class BackwardIterator {
 
 export default class PHPSignatureHelpProvider implements SignatureHelpProvider {
 
-	public provideSignatureHelp(document: TextDocument, position: Position, token: CancellationToken): Promise<SignatureHelp> | null {
+	public provideSignatureHelp(document: TextDocument, position: Position, _token: CancellationToken): Promise<SignatureHelp> | null {
 		let enable = workspace.getConfiguration('php').get<boolean>('suggest.basic', true);
 		if (!enable) {
 			return null;
diff --git a/extensions/php/src/features/utils/async.ts b/extensions/php/src/features/utils/async.ts
index 5093f7c3ebae1908cfb7e8ea5cd1fa7f4cbe418e..78ba0aa582ab8596c61ea91a412d445b8ab88171 100644
--- a/extensions/php/src/features/utils/async.ts
+++ b/extensions/php/src/features/utils/async.ts
@@ -53,7 +53,7 @@ export class Throttler<T> {
 					return result;
 				};
 
-				this.queuedPromise = new Promise<T>((resolve, reject) => {
+				this.queuedPromise = new Promise<T>((resolve) => {
 					this.activePromise!.then(onComplete, onComplete).then(resolve);
 				});
 			}
@@ -121,7 +121,7 @@ export class Delayer<T> {
 		this.cancelTimeout();
 
 		if (!this.completionPromise) {
-			this.completionPromise = new Promise<T>((resolve, reject) => {
+			this.completionPromise = new Promise<T>((resolve) => {
 				this.onResolve = resolve;
 			}).then(() => {
 				this.completionPromise = null;
diff --git a/extensions/php/src/features/validationProvider.ts b/extensions/php/src/features/validationProvider.ts
index 0a26bbd5a9b54a81f21c36a9affacf627043c53b..4f7f8cadbb706395a4e215482b6a3d8738c233ef 100644
--- a/extensions/php/src/features/validationProvider.ts
+++ b/extensions/php/src/features/validationProvider.ts
@@ -224,7 +224,7 @@ export default class PHPValidationProvider {
 	}
 
 	private doValidate(textDocument: vscode.TextDocument): Promise<void> {
-		return new Promise<void>((resolve, reject) => {
+		return new Promise<void>((resolve) => {
 			let executable = this.executable || 'php';
 			let decoder = new LineDecoder();
 			let diagnostics: vscode.Diagnostic[] = [];
diff --git a/extensions/php/tsconfig.json b/extensions/php/tsconfig.json
index b16347a7524fa8e1d966e5d2ce8541ea86b0d7c0..7e9b0d127b409f91d30f5a865bec81bc4e2ba531 100644
--- a/extensions/php/tsconfig.json
+++ b/extensions/php/tsconfig.json
@@ -6,6 +6,10 @@
 		],
 		"module": "commonjs",
 		"outDir": "./out",
+		"noImplicitAny": true,
+		"noImplicitReturns": true,
+		"noUnusedLocals": true,
+		"noUnusedParameters": true,
 		"strict": true
 	},
 	"include": [