diff --git a/custom/conf/app.example.ini b/custom/conf/app.example.ini
index a60a25cdd60..b093b88d9b9 100644
--- a/custom/conf/app.example.ini
+++ b/custom/conf/app.example.ini
@@ -1242,7 +1242,7 @@ LEVEL = Info
 ;DELAY_CHECK_FOR_INACTIVE_DAYS = 7
 ;;
 ;; Set the default value for "Delete pull request branch after merge by default" for new repositories
-;DEFAULT_DELETE_BRANCH_AFTER_MERGE = false
+;DEFAULT_DELETE_BRANCH_AFTER_MERGE = true
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/modules/setting/repository.go b/modules/setting/repository.go
index e8ee37a363c..aecd1fec3e9 100644
--- a/modules/setting/repository.go
+++ b/modules/setting/repository.go
@@ -211,6 +211,7 @@ var (
 			AddCoCommitterTrailers:                   true,
 			RetargetChildrenOnMerge:                  true,
 			DelayCheckForInactiveDays:                7,
+			DefaultDeleteBranchAfterMerge:            true,
 			DefaultTitleSource:                       RepoPRTitleSourceAuto,
 		},
 
diff --git a/tests/e2e/pull-merge-box.test.ts b/tests/e2e/pull-merge-box.test.ts
index 974836fe98d..5f0ae29d029 100644
--- a/tests/e2e/pull-merge-box.test.ts
+++ b/tests/e2e/pull-merge-box.test.ts
@@ -18,6 +18,6 @@ test('merge box merges a pull request', async ({page, request}) => {
   await page.getByRole('button', {name: 'Create merge commit'}).click();
   await page.locator('form.form-fetch-action').getByRole('button', {name: 'Create merge commit'}).click();
 
-  await expect(page.getByText(/successfully merged/i)).toBeVisible();
+  await expect(page.getByText('Merged', {exact: true})).toBeVisible();
   await assertNoJsError(page);
 });
diff --git a/tests/integration/api_pull_test.go b/tests/integration/api_pull_test.go
index 4d4746b4dcb..2edb993e38b 100644
--- a/tests/integration/api_pull_test.go
+++ b/tests/integration/api_pull_test.go
@@ -270,45 +270,36 @@ func TestAPIMergePull(t *testing.T) {
 		t.Run("Normal", func(t *testing.T) {
 			newBranch := "test-pull-1"
 			prDTO := createTestBranchPR(t, newBranch)
-			performMerge(t, prDTO.Index, map[string]any{"do": "merge"})
+			performMerge(t, prDTO.Index, map[string]any{"do": "merge", "delete_branch_after_merge": false})
 			checkBranchExists(t, newBranch, http.StatusOK)
 			// try to merge again, make sure we cannot perform a merge on the same PR
 			performMerge(t, prDTO.Index, map[string]any{"do": "merge"}, http.StatusMethodNotAllowed)
 		})
 
-		t.Run("DeleteBranchAfterMergePassedByFormField", func(t *testing.T) {
+		t.Run("DeleteBranchAfterMergeByDefault", func(t *testing.T) {
 			newBranch := "test-pull-2"
 			prDTO := createTestBranchPR(t, newBranch)
-			performMerge(t, prDTO.Index, map[string]any{"do": "merge", "delete_branch_after_merge": true})
+			performMerge(t, prDTO.Index, map[string]any{"do": "merge"})
 			checkBranchExists(t, newBranch, http.StatusNotFound)
 		})
 
-		updateRepoUnitDefaultDeleteBranchAfterMerge := func(t *testing.T, repo *repo_model.Repository, value bool) {
+		t.Run("DeleteBranchAfterMergeDisabledByRepoSettings", func(t *testing.T) {
 			prUnit, err := repo.GetUnit(t.Context(), unit_model.TypePullRequests)
 			require.NoError(t, err)
-
-			prUnit.PullRequestsConfig().DefaultDeleteBranchAfterMerge = value
+			prUnit.PullRequestsConfig().DefaultDeleteBranchAfterMerge = false
 			require.NoError(t, repo_service.UpdateRepositoryUnits(t.Context(), repo, []repo_model.RepoUnit{{
 				RepoID: repo.ID,
 				Type:   unit_model.TypePullRequests,
 				Config: prUnit.PullRequestsConfig(),
 			}}, nil))
-		}
 
-		t.Run("DeleteBranchAfterMergePassedByRepoSettings", func(t *testing.T) {
-			newBranch := "test-pull-3"
-			prDTO := createTestBranchPR(t, newBranch)
-			updateRepoUnitDefaultDeleteBranchAfterMerge(t, repo, true)
-			performMerge(t, prDTO.Index, map[string]any{"do": "merge"})
-			checkBranchExists(t, newBranch, http.StatusNotFound)
-		})
+			keptPR := createTestBranchPR(t, "test-pull-3")
+			performMerge(t, keptPR.Index, map[string]any{"do": "merge"})
+			checkBranchExists(t, "test-pull-3", http.StatusOK)
 
-		t.Run("DeleteBranchAfterMergeFormFieldIsSetButNotRepoSettings", func(t *testing.T) {
-			newBranch := "test-pull-4"
-			prDTO := createTestBranchPR(t, newBranch)
-			updateRepoUnitDefaultDeleteBranchAfterMerge(t, repo, false)
-			performMerge(t, prDTO.Index, map[string]any{"do": "merge", "delete_branch_after_merge": true})
-			checkBranchExists(t, newBranch, http.StatusNotFound)
+			deletedPR := createTestBranchPR(t, "test-pull-4")
+			performMerge(t, deletedPR.Index, map[string]any{"do": "merge", "delete_branch_after_merge": true})
+			checkBranchExists(t, "test-pull-4", http.StatusNotFound)
 		})
 
 		t.Run("SquashMergePreservesFormMessage", func(t *testing.T) {
diff --git a/tests/integration/pull_merge_test.go b/tests/integration/pull_merge_test.go
index c969d078c66..177abc046f8 100644
--- a/tests/integration/pull_merge_test.go
+++ b/tests/integration/pull_merge_test.go
@@ -1215,7 +1215,6 @@ func TestPullSquashMessage(t *testing.T) {
 		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
 		user2Session := loginUser(t, user2.Name)
 
-		defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultSquashMergeMessage, "COMMIT_MESSAGES")()
 		defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultMergeMessageSize, 80)()
 
 		repo, err := repo_service.CreateRepository(t.Context(), user2, user2, repo_service.CreateRepoOptions{
@@ -1226,6 +1225,14 @@ func TestPullSquashMessage(t *testing.T) {
 			DefaultBranch: "main",
 		})
 		require.NoError(t, err)
+		prUnit, err := repo.GetUnit(t.Context(), unit_model.TypePullRequests)
+		require.NoError(t, err)
+		prUnit.PullRequestsConfig().DefaultSquashMergeMessage = repo_model.SquashMergeMessageCommitMessages
+		require.NoError(t, repo_service.UpdateRepositoryUnits(t.Context(), repo, []repo_model.RepoUnit{{
+			RepoID: repo.ID,
+			Type:   unit_model.TypePullRequests,
+			Config: prUnit.PullRequestsConfig(),
+		}}, nil))
 
 		type commitInfo struct {
 			userName      string
@@ -1352,8 +1359,6 @@ Co-authored-by: user4 <user4@example.com>
 			pullRequest.Issue.Content = "PR description"
 			pullRequest.BaseRepo = repo
 
-			prUnit, err := repo.GetUnit(t.Context(), unit_model.TypePullRequests)
-			require.NoError(t, err)
 			for style, expected := range map[repo_model.SquashMergeMessage]string{
 				repo_model.SquashMergeMessageBlank:  "",
 				repo_model.SquashMergeMessagePRBody: "PR description",
@@ -1366,7 +1371,6 @@ Co-authored-by: user4 <user4@example.com>
 		})
 
 		t.Run("API squash merge without message uses repository default", func(t *testing.T) {
-			defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultSquashMergeMessage, "PR_BODY")()
 			token := getTokenForLoggedInUser(t, user2Session, auth_model.AccessTokenScopeWriteRepository)
 			req := NewRequestWithJSON(t, "POST", fmt.Sprintf("/api/v1/repos/%s/%s/pulls/1/merge", user2.Name, repo.Name), map[string]string{"do": "squash"}).AddTokenAuth(token)
 			MakeRequest(t, req, http.StatusOK)