diff --git a/src/template_parser.rs b/src/template_parser.rs
index 0dd55984b..668288f01 100644
--- a/src/template_parser.rs
+++ b/src/template_parser.rs
@@ -191,7 +191,9 @@ fn parse_string_method<'a>(name: Pair<Rule>, _args: Pairs<Rule>) -> Property<'a,
     }
     // TODO: validate arguments
     match name.as_str() {
-        "first_line" => Property::String(wrap_fn(|s| s.lines().next().unwrap().to_string())),
+        "first_line" => Property::String(wrap_fn(|s| {
+            s.lines().next().unwrap_or_default().to_string()
+        })),
         name => panic!("no such string method: {name}"),
     }
 }
diff --git a/tests/test_templater.rs b/tests/test_templater.rs
index b6f4c2515..24a57a4af 100644
--- a/tests/test_templater.rs
+++ b/tests/test_templater.rs
@@ -105,6 +105,17 @@ fn test_templater_parsed_tree() {
     insta::assert_snapshot!(render(r#"if((divergent), "t", "f")"#), @"f");
 }
 
+#[test]
+fn test_templater_string_method() {
+    let test_env = TestEnvironment::default();
+    test_env.jj_cmd_success(test_env.env_root(), &["init", "repo", "--git"]);
+    let repo_path = test_env.env_root().join("repo");
+    let render = |template| get_template_output(&test_env, &repo_path, "@-", template);
+
+    insta::assert_snapshot!(render(r#""".first_line()"#), @"");
+    insta::assert_snapshot!(render(r#""foo\nbar".first_line()"#), @"foo");
+}
+
 fn get_template_output(
     test_env: &TestEnvironment,
     repo_path: &Path,