diff --git a/mdformat_mkdocs/plugin.py b/mdformat_mkdocs/plugin.py
index 11377cd..b52b675 100644
--- a/mdformat_mkdocs/plugin.py
+++ b/mdformat_mkdocs/plugin.py
@@ -15,9 +15,8 @@
 def update_mdit(mdit: MarkdownIt) -> None:
     """No changes to markdown parsing are necessary."""
     global _ALIGN_SEMANTIC_BREAKS_IN_NUMBERED_LISTS
-    # FIXME: How do I add this configuration option?
-    _ALIGN_SEMANTIC_BREAKS_IN_NUMBERED_LISTS = mdit.options.get(
-        "align_semantic_breaks_in_numbered_lists", True
+    _ALIGN_SEMANTIC_BREAKS_IN_NUMBERED_LISTS = mdit.options.get("mdformat", {}).get(
+        "align_semantic_breaks_in_numbered_lists", False
     )
 
 
diff --git a/tests/fixtures.md b/tests/fixtures.md
index 6949911..278e12c 100644
--- a/tests/fixtures.md
+++ b/tests/fixtures.md
@@ -173,15 +173,15 @@ Hanging List (https://github.com/executablebooks/mdformat/issues/371)
      Otherwise this next paragraph doesn't belong in the same list item.
 .
 1. Here indent width is
-   three.
+    three.
 
     1. Here indent width is
-       three.
+        three.
 
 1. Here indent width is
-   five. It needs to be so, because
+    five. It needs to be so, because
 
-   Otherwise this next paragraph doesn't belong in the same list item.
+    Otherwise this next paragraph doesn't belong in the same list item.
 .
 
 Table
diff --git a/tests/test_align_semantic_breaks_in_numbered_lists.py b/tests/test_align_semantic_breaks_in_numbered_lists.py
new file mode 100644
index 0000000..644176d
--- /dev/null
+++ b/tests/test_align_semantic_breaks_in_numbered_lists.py
@@ -0,0 +1,37 @@
+import mdformat
+
+
+def test_align_semantic_breaks_in_numbered_lists():
+    """For https://github.com/KyleKing/mdformat-mkdocs/issues/4."""
+    input_text = """\
+1. Here indent width is
+   three.
+
+      2. Here indent width is
+       three.
+
+123. Here indent width is
+     five. It needs to be so, because
+
+     Otherwise this next paragraph doesn't belong in the same list item.
+"""
+    expected_output = """\
+1. Here indent width is
+   three.
+
+    1. Here indent width is
+       three.
+
+1. Here indent width is
+   five. It needs to be so, because
+
+   Otherwise this next paragraph doesn't belong in the same list item.
+"""
+
+    output = mdformat.text(
+        input_text,
+        options={"align_semantic_breaks_in_numbered_lists": True},
+        extensions={"mkdocs"},
+    )
+
+    assert output == expected_output