diff --git a/extensions/git/src/git.ts b/extensions/git/src/git.ts
index 5e1eb1925dc78..431d50b88afee 100644
--- a/extensions/git/src/git.ts
+++ b/extensions/git/src/git.ts
@@ -1374,7 +1374,10 @@ export class Repository {
 				throw new GitError({ message: 'Path not known by git', gitErrorCode: GitErrorCodes.UnknownPath });
 			}
 
-			const { mode, object } = elements[0];
+			const { mode, object } = treeish !== ''
+				? elements.find(e => e.stage === treeish.substring(1)) ?? elements[0]
+				: elements[0];
+
 			const catFile = await this.exec(['cat-file', '-s', object]);
 			const size = parseInt(catFile.stdout);