diff --git a/extensions/vscode-api-tests/src/window.test.ts b/extensions/vscode-api-tests/src/window.test.ts
index 5cf72ddea15..9273df47d30 100644
--- a/extensions/vscode-api-tests/src/window.test.ts
+++ b/extensions/vscode-api-tests/src/window.test.ts
@@ -315,7 +315,7 @@ suite('window namespace tests', () => {
 		assert.equal(terminal.name, 'foo');
 
 		assert.throws(() => {
-			terminal.name = 'bar';
+			(<any>terminal).name = 'bar';
 		}, 'Terminal.name should be readonly');
 	});
 
diff --git a/extensions/vscode-api-tests/src/workspace.test.ts b/extensions/vscode-api-tests/src/workspace.test.ts
index b963ab62af5..0b4e2c01118 100644
--- a/extensions/vscode-api-tests/src/workspace.test.ts
+++ b/extensions/vscode-api-tests/src/workspace.test.ts
@@ -24,7 +24,7 @@ suite('workspace-namespace', () => {
 		assert.equal(config['config0'], true);
 		assert.equal(config['config4'], '');
 
-		assert.throws(() => config['config4'] = 'valuevalue');
+		assert.throws(() => (<any>config)['config4'] = 'valuevalue');
 
 		assert.ok(config.has('nested.config1'));
 		assert.equal(config.get('nested.config1'), 42);