diff --git a/src/vs/base/node/config.ts b/src/vs/base/node/config.ts
index 5d71bada8826aab949e9e241e086037866f728f6..d08120cfbfcd07925068d17c07fa17f06cfed4cb 100644
--- a/src/vs/base/node/config.ts
+++ b/src/vs/base/node/config.ts
@@ -171,7 +171,7 @@ export class ConfigWatcher<T> implements IConfigWatcher<T>, IDisposable {
 			// Windows: in some cases the filename contains artifacts from the absolute path
 			// see https://github.com/nodejs/node/issues/19170
 			// As such, we have to ensure that the filename basename is used for comparison.
-			if (isWindows && filename !== this.configName) {
+			if (isWindows && filename && filename !== this.configName) {
 				filename = basename(filename);
 			}
 
diff --git a/src/vs/base/node/extfs.ts b/src/vs/base/node/extfs.ts
index 0dbc27ed24cc99d8f2dde169588c599e690187fa..3ffedc2d347e4c671566fb1f7bcfd97fb77be97e 100644
--- a/src/vs/base/node/extfs.ts
+++ b/src/vs/base/node/extfs.ts
@@ -620,7 +620,7 @@ function normalizePath(path: string): string {
 	return strings.rtrim(paths.normalize(path), paths.sep);
 }
 
-export function watch(path: string, onChange: (type: string, path: string) => void, onError: (error: string) => void): fs.FSWatcher {
+export function watch(path: string, onChange: (type: string, path?: string) => void, onError: (error: string) => void): fs.FSWatcher {
 	try {
 		const watcher = fs.watch(path);