diff --git a/packages/fleather/lib/src/widgets/autoformats.dart b/packages/fleather/lib/src/widgets/autoformats.dart
index a811dea5..f03df9eb 100644
--- a/packages/fleather/lib/src/widgets/autoformats.dart
+++ b/packages/fleather/lib/src/widgets/autoformats.dart
@@ -28,12 +28,15 @@ class AutoFormats {
       : _autoFormats = autoFormats;
 
   /// Default set of auto formats.
-  factory AutoFormats.fallback() {
+  ///
+  /// Use [additionalFormats] to add your autoformats to the default set.
+  factory AutoFormats.fallback([List<AutoFormat>? additionalFormats]) {
     return AutoFormats(autoFormats: [
-      const _AutoFormatLinks(),
-      const _MarkdownInlineShortcuts(),
-      const _MarkdownLineShortcuts(),
-      const _AutoTextDirection(),
+      const AutoFormatLinks(),
+      const MarkdownInlineShortcuts(),
+      const MarkdownLineShortcuts(),
+      const AutoTextDirection(),
+      ...?additionalFormats,
     ]);
   }
 
@@ -119,11 +122,11 @@ class AutoFormatResult {
   final int undoPositionCandidate;
 }
 
-class _AutoFormatLinks extends AutoFormat {
+class AutoFormatLinks extends AutoFormat {
   static final _urlRegex =
       RegExp(r'^(.?)((?:https?://|www\.)[^\s/$.?#].[^\s]*)');
 
-  const _AutoFormatLinks();
+  const AutoFormatLinks();
 
   @override
   AutoFormatResult? apply(
@@ -166,7 +169,7 @@ class _AutoFormatLinks extends AutoFormat {
 }
 
 // Replaces certain Markdown shortcuts with actual inline styles.
-class _MarkdownInlineShortcuts extends AutoFormat {
+class MarkdownInlineShortcuts extends AutoFormat {
   static final rules = <String, ParchmentAttribute>{
     '**': ParchmentAttribute.bold,
     '*': ParchmentAttribute.italic,
@@ -174,7 +177,7 @@ class _MarkdownInlineShortcuts extends AutoFormat {
     '~~': ParchmentAttribute.strikethrough,
   };
 
-  const _MarkdownInlineShortcuts();
+  const MarkdownInlineShortcuts();
 
   @override
   AutoFormatResult? apply(
@@ -222,7 +225,7 @@ class _MarkdownInlineShortcuts extends AutoFormat {
 }
 
 // Replaces certain Markdown shortcuts with actual line or block styles.
-class _MarkdownLineShortcuts extends AutoFormat {
+class MarkdownLineShortcuts extends AutoFormat {
   static final rules = <String, ParchmentAttribute>{
     '-': ParchmentAttribute.block.bulletList,
     '*': ParchmentAttribute.block.bulletList,
@@ -236,7 +239,7 @@ class _MarkdownLineShortcuts extends AutoFormat {
     '###': ParchmentAttribute.h3,
   };
 
-  const _MarkdownLineShortcuts();
+  const MarkdownLineShortcuts();
 
   String? _getLinePrefix(DeltaIterator iter, int index) {
     final prefixOps = skipToLineAt(iter, index);
@@ -383,8 +386,8 @@ class _MarkdownLineShortcuts extends AutoFormat {
 
 // Infers text direction from the input when happens in the beginning of a line.
 // This rule also removes alignment and sets it based on inferred direction.
-class _AutoTextDirection extends AutoFormat {
-  const _AutoTextDirection();
+class AutoTextDirection extends AutoFormat {
+  const AutoTextDirection();
 
   final _isRTL = intl.Bidi.startsWithRtl;
 
diff --git a/packages/fleather/test/widgets/autoformats_test.dart b/packages/fleather/test/widgets/autoformats_test.dart
index 17c233bf..b1220508 100644
--- a/packages/fleather/test/widgets/autoformats_test.dart
+++ b/packages/fleather/test/widgets/autoformats_test.dart
@@ -1,12 +1,21 @@
 import 'package:fleather/fleather.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:mocktail/mocktail.dart';
 
 void main() {
   late AutoFormats autoformats;
 
   setUp(() {
     autoformats = AutoFormats.fallback();
+    registerFallbackValue(ParchmentDocument());
+  });
+
+  test('Can use custom formats with fallbacks', () {
+    final document = ParchmentDocument();
+    final formats = AutoFormats.fallback([FakeAutoFormat('.')]);
+    expect(formats.run(document, 0, '.'), isTrue);
+    expect(document.toDelta(), Delta()..insert('Fake\n'));
   });
 
   group('Link detection', () {
@@ -265,3 +274,28 @@ void main() {
     });
   });
 }
+
+class FakeAutoFormat extends AutoFormat {
+  final String trigger;
+
+  FakeAutoFormat(this.trigger);
+
+  @override
+  AutoFormatResult? apply(
+      ParchmentDocument document, int position, String data) {
+    if (data == trigger) {
+      final change = Delta()
+        ..retain(position)
+        ..insert('Fake');
+      document.compose(change, ChangeSource.local);
+      return AutoFormatResult(
+        change: change,
+        undo: Delta()
+          ..retain(position)
+          ..delete(4),
+        undoPositionCandidate: position,
+      );
+    }
+    return null;
+  }
+}