diff --git a/src/activateMockDebug.ts b/src/activateMockDebug.ts
index e3bc85e..0e83b96 100644
--- a/src/activateMockDebug.ts
+++ b/src/activateMockDebug.ts
@@ -183,6 +183,7 @@ class MockConfigurationProvider implements vscode.DebugConfigurationProvider {
 }
 
 export const workspaceFileAccessor: FileAccessor = {
+	isWindows: false,
 	async readFile(path: string): Promise<Uint8Array> {
 		let uri: vscode.Uri;
 		try {
diff --git a/src/debugAdapter.ts b/src/debugAdapter.ts
index 63f7b3f..52d1cc4 100644
--- a/src/debugAdapter.ts
+++ b/src/debugAdapter.ts
@@ -17,6 +17,7 @@ import { FileAccessor } from './mockRuntime';
  * So we can only use node.js API for accessing files.
  */
 const fsAccessor:  FileAccessor = {
+	isWindows: process.platform === 'win32',
 	readFile(path: string): Promise<Uint8Array> {
 		return fs.readFile(path);
 	},
diff --git a/src/mockRuntime.ts b/src/mockRuntime.ts
index e4e5d04..1bebfe7 100644
--- a/src/mockRuntime.ts
+++ b/src/mockRuntime.ts
@@ -5,6 +5,7 @@
 import { EventEmitter } from 'events';
 
 export interface FileAccessor {
+	isWindows: boolean;
 	readFile(path: string): Promise<Uint8Array>;
 	writeFile(path: string, contents: Uint8Array): Promise<void>;
 }
@@ -674,7 +675,7 @@ export class MockRuntime extends EventEmitter {
 	}
 
 	private normalizePathAndCasing(path: string) {
-		if (process.platform === 'win32') {
+		if (this.fileAccessor.isWindows) {
 			return path.replace(/\//g, '\\').toLowerCase();
 		} else {
 			return path.replace(/\\/g, '/');