diff --git a/mdit_py_plugins/tasklists/__init__.py b/mdit_py_plugins/tasklists/__init__.py
index 089bb5d..81a9bd4 100644
--- a/mdit_py_plugins/tasklists/__init__.py
+++ b/mdit_py_plugins/tasklists/__init__.py
@@ -108,12 +108,14 @@ def todoify(token: Token) -> None:
     def make_checkbox(token: Token) -> Token:
         checkbox = Token("html_inline", "", 0)
         disabled_attr = 'disabled="disabled"' if disable_checkboxes else ""
-        if token.content.startswith("[ ] "):
+        # starts_with_todo_markdown already matched "[ ]", "[x]" or "[X]" followed by
+        # any GFM whitespace, so only the character inside the brackets matters here
+        if token.content[1] == " ":
             checkbox.content = (
                 '<input class="task-list-item-checkbox" '
                 f'{disabled_attr} type="checkbox">'
             )
-        elif token.content.startswith("[x] ") or token.content.startswith("[X] "):
+        else:
             checkbox.content = (
                 '<input class="task-list-item-checkbox" checked="checked" '
                 f'{disabled_attr} type="checkbox">'
diff --git a/tests/fixtures/tasklists.md b/tests/fixtures/tasklists.md
index dec0fef..9b209f2 100644
--- a/tests/fixtures/tasklists.md
+++ b/tests/fixtures/tasklists.md
@@ -114,8 +114,8 @@ Tab after task list item marker
 + [ ]		item 2
 .
 <ul class="contains-task-list">
-<li class="task-list-item">	item 1</li>
-<li class="task-list-item">		item 2</li>
+<li class="task-list-item"><input class="task-list-item-checkbox" checked="checked" disabled="disabled" type="checkbox">	item 1</li>
+<li class="task-list-item"><input class="task-list-item-checkbox" disabled="disabled" type="checkbox">		item 2</li>
 </ul>
 .
 
@@ -125,7 +125,7 @@ Form feed after task list item marker
 + [ ]item 2
 .
 <ul class="contains-task-list">
-<li class="task-list-item">item 1</li>
-<li class="task-list-item">item 2</li>
+<li class="task-list-item"><input class="task-list-item-checkbox" checked="checked" disabled="disabled" type="checkbox">item 1</li>
+<li class="task-list-item"><input class="task-list-item-checkbox" disabled="disabled" type="checkbox">item 2</li>
 </ul>
 .
diff --git a/tests/test_tasklists.py b/tests/test_tasklists.py
index 7a21218..54a30e0 100644
--- a/tests/test_tasklists.py
+++ b/tests/test_tasklists.py
@@ -45,6 +45,8 @@ def test_all(line, title, input, expected):
         ),
         pytest.param("- [x] a & b\n", " a &amp; b", id="ampersand"),
         pytest.param("- [ ] plain task\n", " plain task", id="plain"),
+        pytest.param("- [ ]\tplain task\n", "\tplain task", id="tab-unchecked"),
+        pytest.param("- [x]\tplain task\n", "\tplain task", id="tab-checked"),
     ],
 )
 def test_label_after_is_escaped(source, label):