diff --git a/src/controller/testController.ts b/src/controller/testController.ts
index bae0f2e5..05e1feea 100644
--- a/src/controller/testController.ts
+++ b/src/controller/testController.ts
@@ -167,7 +167,7 @@ export const runTests: (request: TestRunRequest, option: IRunOption) => any = in
     }
 
     const run: TestRun = testController!.createTestRun(request);
-    const coverageProvider = new JavaTestCoverageProvider();
+    const coverageProvider: JavaTestCoverageProvider = new JavaTestCoverageProvider();
     try {
         await new Promise<void>(async (resolve: () => void): Promise<void> => {
             const token: CancellationToken = option.token ?? run.token;
diff --git a/src/provider/JavaTestCoverageProvider.ts b/src/provider/JavaTestCoverageProvider.ts
index 300bad68..bcfb7ef1 100644
--- a/src/provider/JavaTestCoverageProvider.ts
+++ b/src/provider/JavaTestCoverageProvider.ts
@@ -28,18 +28,20 @@ export class JavaTestCoverageProvider implements TestCoverageProvider {
             }
 
             for (const sourceFileCoverage of sourceFileCoverages) {
-                const uri = Uri.file(Uri.parse(sourceFileCoverage.uriString).fsPath);
+                const uri: Uri = Uri.file(Uri.parse(sourceFileCoverage.uriString).fsPath);
                 const detailedCoverage: DetailedCoverage[] = [];
                 for (const lineCoverage of sourceFileCoverage.lineCoverages) {
                     const branchCoverages: BranchCoverage[] = [];
                     for (const branchCoverage of lineCoverage.branchCoverages) {
                         branchCoverages.push(new BranchCoverage(branchCoverage.hit, new Position(lineCoverage.lineNumber - 1, 0)));
                     }
-                    const statementCoverage = new StatementCoverage(lineCoverage.hit, new Position(lineCoverage.lineNumber - 1, 0), branchCoverages);
+                    const statementCoverage: StatementCoverage = new StatementCoverage(lineCoverage.hit,
+                        new Position(lineCoverage.lineNumber - 1, 0), branchCoverages);
                     detailedCoverage.push(statementCoverage);
                 }
                 for (const methodCoverage of sourceFileCoverage.methodCoverages) {
-                    const functionCoverage = new FunctionCoverage(methodCoverage.name, methodCoverage.hit, new Position(methodCoverage.lineNumber - 1, 0));
+                    const functionCoverage: FunctionCoverage = new FunctionCoverage(methodCoverage.name, methodCoverage.hit,
+                        new Position(methodCoverage.lineNumber - 1, 0));
                     detailedCoverage.push(functionCoverage);
                 }
                 fileCoverages.push(FileCoverage.fromDetails(uri, detailedCoverage));
diff --git a/src/types.ts b/src/types.ts
index a986470e..f453411d 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,7 +1,8 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license.
 
-import { Range, TestItem, TestRun, TestRunProfile, WorkspaceFolder } from 'vscode';
+import { Range, TestItem, TestRun, TestRunProfile } from 'vscode';
+import * as vscode from 'vscode';
 
 export interface IJavaTestItem {
     children: IJavaTestItem[];
@@ -54,7 +55,7 @@ export interface IRunTestContext {
     projectName: string;
     testItems: TestItem[];
     testRun: TestRun;
-    workspaceFolder: WorkspaceFolder;
+    workspaceFolder: vscode.WorkspaceFolder;
     profile?: TestRunProfile;
 }
 
diff --git a/src/utils/launchUtils.ts b/src/utils/launchUtils.ts
index 32f8d519..9b8a0f19 100644
--- a/src/utils/launchUtils.ts
+++ b/src/utils/launchUtils.ts
@@ -83,7 +83,7 @@ export async function resolveLaunchConfigurationForRunner(runner: BaseRunner, te
     }
 
     if (testContext.profile?.label.includes('Coverage')) {
-        let agentArg = `-javaagent:${getJacocoAgentPath()}=destfile=${getJacocoDataFilePath(launchArguments.projectName)}`;
+        let agentArg: string = `-javaagent:${getJacocoAgentPath()}=destfile=${getJacocoDataFilePath(launchArguments.projectName)}`;
         if (config?.coverage?.appendResult === false) {
             agentArg += ',append=false';
         }