diff --git a/extensions/git/src/git.ts b/extensions/git/src/git.ts
index dc4829808b4ed1cba1c5a0e36e4f3c7e10ae9140..b2c111a46fe893a7e87503c3211982c01c9454ff 100644
--- a/extensions/git/src/git.ts
+++ b/extensions/git/src/git.ts
@@ -481,6 +481,7 @@ export class Git {
 export interface Commit {
 	hash: string;
 	message: string;
+	previousHashes: string[];
 }
 
 export class GitStatusParser {
@@ -1287,14 +1288,14 @@ export class Repository {
 	}
 
 	async getCommit(ref: string): Promise<Commit> {
-		const result = await this.run(['show', '-s', '--format=%H\n%B', ref]);
-		const match = /^([0-9a-f]{40})\n([^]*)$/m.exec(result.stdout.trim());
+		const result = await this.run(['show', '-s', '--format=%H\n%P\n%B', ref]);
+		const match = /^([0-9a-f]{40})\n(.*)\n([^]*)$/m.exec(result.stdout.trim());
 
 		if (!match) {
 			return Promise.reject<Commit>('bad commit format');
 		}
 
-		return { hash: match[1], message: match[2] };
+		return { hash: match[1], message: match[3], previousHashes: [match[2]] };
 	}
 
 	async updateSubmodules(paths: string[]): Promise<void> {
diff --git a/extensions/git/src/test/git.test.ts b/extensions/git/src/test/git.test.ts
index 39c9f0a7e9fc17012d509ef2daf149998597d9b7..af4a24c349bf00feb7e7217f6e717fdbbbc5b3fa 100644
--- a/extensions/git/src/test/git.test.ts
+++ b/extensions/git/src/test/git.test.ts
@@ -181,16 +181,18 @@ suite('git', () => {
 		test('get commit', async () => {
 			const spawnOption = {};
 			const gitOutput = `52c293a05038d865604c2284aa8698bd087915a1
+8e5a374372b8393906c7e380dbb09349c5385554
 This is a commit message.`;
 			const git = sinon.createStubInstance(Git);
 			git.exec = sinon.stub()
-				.withArgs('REPOSITORY_ROOT', ['show', '-s', '--format=%H\n%B', 'REF'], spawnOption)
+				.withArgs('REPOSITORY_ROOT', ['show', '-s', '--format=%H\n%P\n%B', 'REF_SINGLE_PARENT'], spawnOption)
 				.returns(Promise.resolve({stdout: gitOutput}));
 			const repository = new Repository(git, 'REPOSITORY_ROOT');
 
-			assert.deepEqual(await repository.getCommit('REF'), {
+			assert.deepEqual(await repository.getCommit('REF_SINGLE_PARENT'), {
 				hash: '52c293a05038d865604c2284aa8698bd087915a1',
-				message: 'This is a commit message.'
+				message: 'This is a commit message.',
+				previousHashes: ['8e5a374372b8393906c7e380dbb09349c5385554']
 			});
 		});
 	});