diff --git a/extensions/git/src/fileSystemProvider.ts b/extensions/git/src/fileSystemProvider.ts
index 8b8f9fc65af..19928863832 100644
--- a/extensions/git/src/fileSystemProvider.ts
+++ b/extensions/git/src/fileSystemProvider.ts
@@ -18,7 +18,7 @@ interface CacheRow {
 const THREE_MINUTES = 1000 * 60 * 3;
 const FIVE_MINUTES = 1000 * 60 * 5;
 
-function sanitizeRef(ref: string, path: string, repository: Repository): string {
+function sanitizeRef(ref: string, path: string, submoduleOf: string | undefined, repository: Repository): string {
 	if (ref === '~') {
 		const fileUri = Uri.file(path);
 		const uriString = fileUri.toString();
@@ -30,6 +30,11 @@ function sanitizeRef(ref: string, path: string, repository: Repository): string
 		return `:${ref[1]}`;
 	}
 
+	// Submodule HEAD
+	if (submoduleOf && (ref === 'index' || ref === 'wt')) {
+		return 'HEAD';
+	}
+
 	return ref;
 }
 
@@ -141,7 +146,7 @@ export class GitFileSystemProvider implements FileSystemProvider {
 		}
 
 		try {
-			const details = await repository.getObjectDetails(sanitizeRef(ref, path, repository), path);
+			const details = await repository.getObjectDetails(sanitizeRef(ref, path, submoduleOf, repository), path);
 			return { type: FileType.File, size: details.size, mtime: this.mtime, ctime: 0 };
 		} catch {
 			// Empty tree
@@ -198,7 +203,7 @@ export class GitFileSystemProvider implements FileSystemProvider {
 		this.cache.set(uri.toString(), cacheValue);
 
 		try {
-			return await repository.buffer(sanitizeRef(ref, path, repository), path);
+			return await repository.buffer(sanitizeRef(ref, path, submoduleOf, repository), path);
 		} catch {
 			// Empty tree
 			if (ref === await repository.getEmptyTree()) {
diff --git a/extensions/git/src/git.ts b/extensions/git/src/git.ts
index 1026faefacb..2944f1d2f17 100644
--- a/extensions/git/src/git.ts
+++ b/extensions/git/src/git.ts
@@ -1392,7 +1392,7 @@ export class Repository {
 		}
 
 		const { mode, object, size } = elements[0];
-		return { mode, object, size: parseInt(size) };
+		return { mode, object, size: parseInt(size) || 0 };
 	}
 
 	async lstree(treeish: string, path?: string): Promise<LsTreeElement[]> {