diff --git a/api/queries_pr.go b/api/queries_pr.go
index 37a1c27df..5ebaaa613 100644
--- a/api/queries_pr.go
+++ b/api/queries_pr.go
@@ -981,13 +981,18 @@ func PullRequestMerge(client *Client, repo ghrepo.Interface, pr *PullRequest, m
 		} `graphql:"mergePullRequest(input: $input)"`
 	}
 
-	commitHeadline := githubv4.String(fmt.Sprintf("%s (#%d)", pr.Title, pr.Number))
+	input := githubv4.MergePullRequestInput{
+		PullRequestID: pr.ID,
+		MergeMethod:   &mergeMethod,
+	}
+
+	if m == PullRequestMergeMethodSquash {
+		commitHeadline := githubv4.String(fmt.Sprintf("%s (#%d)", pr.Title, pr.Number))
+		input.CommitHeadline = &commitHeadline
+	}
+
 	variables := map[string]interface{}{
-		"input": githubv4.MergePullRequestInput{
-			PullRequestID:  pr.ID,
-			MergeMethod:    &mergeMethod,
-			CommitHeadline: &commitHeadline,
-		},
+		"input": input,
 	}
 
 	gql := graphQLClient(client.http, repo.RepoHost())
diff --git a/pkg/cmd/pr/merge/merge_test.go b/pkg/cmd/pr/merge/merge_test.go
index 2b5f89e7b..6abea963c 100644
--- a/pkg/cmd/pr/merge/merge_test.go
+++ b/pkg/cmd/pr/merge/merge_test.go
@@ -189,6 +189,7 @@ func TestPrMerge(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -234,6 +235,7 @@ func TestPrMerge_nontty(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -276,6 +278,7 @@ func TestPrMerge_withRepoFlag(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -310,6 +313,7 @@ func TestPrMerge_deleteBranch(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "PR_10", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -344,6 +348,7 @@ func TestPrMerge_deleteNonCurrentBranch(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "PR_10", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -376,6 +381,7 @@ func TestPrMerge_noPrNumberGiven(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "PR_10", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -421,6 +427,7 @@ func TestPrMerge_rebase(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "REBASE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -465,6 +472,7 @@ func TestPrMerge_squash(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "SQUASH", input["mergeMethod"].(string))
+			assert.Equal(t, "The title of the PR (#3)", input["commitHeadline"].(string))
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),
@@ -533,6 +541,7 @@ func TestPRMerge_interactive(t *testing.T) {
 		httpmock.GraphQLMutation(`{}`, func(input map[string]interface{}) {
 			assert.Equal(t, "THE-ID", input["pullRequestId"].(string))
 			assert.Equal(t, "MERGE", input["mergeMethod"].(string))
+			assert.NotContains(t, input, "commitHeadline")
 		}))
 	http.Register(
 		httpmock.REST("DELETE", "repos/OWNER/REPO/git/refs/heads/blueberries"),