diff --git a/flutter_readium_platform_interface/CHANGELOG.md b/flutter_readium_platform_interface/CHANGELOG.md
index c2fc0d08..3ac847cc 100644
--- a/flutter_readium_platform_interface/CHANGELOG.md
+++ b/flutter_readium_platform_interface/CHANGELOG.md
@@ -5,6 +5,12 @@ Format follows [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## Unreleased
 
+### Fixed
+
+- `ReadiumTimebasedState.fromJson()` now tolerates audiobook terminal locators
+  that omit `progression` / `totalProgression`, preserving the locator while
+  normalizing ended-state progress to `1.0` instead of crashing on Android.
+
 ## [0.3.3] - 2026-08-04
 
 ## [0.3.2] - 2026-08-03
diff --git a/flutter_readium_platform_interface/lib/src/shared/publication/locator.dart b/flutter_readium_platform_interface/lib/src/shared/publication/locator.dart
index c214a45a..72214de0 100644
--- a/flutter_readium_platform_interface/lib/src/shared/publication/locator.dart
+++ b/flutter_readium_platform_interface/lib/src/shared/publication/locator.dart
@@ -21,13 +21,7 @@ import 'link.dart';
 const int _emptyIntValue = -1;
 const double _emptyDoubleValue = -1;
 
-extension IntCheck on int? {
-  int? check(int? defaultValue) => (this == _emptyIntValue) ? defaultValue : this;
-}
-
-extension DoubleNullableCheck on double? {
-  double? check(double? defaultValue) => (this == _emptyDoubleValue) ? defaultValue : this;
-
+extension DoubleNullableRound on double? {
   /// Ensure that this double? is within [epsilon] of [defaultValue], otherwise return this double? (or defaultValue if this is null).
   double roundToIfCloseTo(
     double defaultValue, {
@@ -183,9 +177,9 @@ class Locator extends AdditionalProperties with Equatable implements JSONable {
   }) => copyWith(
     locations: (locations ?? Locations()).copyWith(
       fragments: fragments ?? locations?.fragments,
-      progression: progression.check(locations?.progression),
-      position: position.check(locations?.position),
-      totalProgression: totalProgression.check(locations?.totalProgression),
+      progression: progression == _emptyDoubleValue ? locations?.progression : progression,
+      position: position == _emptyIntValue ? locations?.position : position,
+      totalProgression: totalProgression == _emptyDoubleValue ? locations?.totalProgression : totalProgression,
       additionalProperties: otherLocations ?? locations?.additionalProperties,
     ),
   );
@@ -326,9 +320,9 @@ class Locations extends AdditionalProperties with Equatable implements JSONable
       ..removeWhere((key, value) => value == null);
 
     return Locations(
-      progression: progression.check(this.progression),
-      position: position.check(this.position),
-      totalProgression: totalProgression.check(this.totalProgression),
+      progression: progression == _emptyDoubleValue ? this.progression : progression,
+      position: position == _emptyIntValue ? this.position : position,
+      totalProgression: totalProgression == _emptyDoubleValue ? this.totalProgression : totalProgression,
       fragments: fragments ?? this.fragments,
       cssSelector: cssSelector ?? this.cssSelector,
       domRange: domRange ?? this.domRange,
diff --git a/flutter_readium_platform_interface/test/models_test.dart b/flutter_readium_platform_interface/test/models_test.dart
index ac44010a..018f9a2c 100644
--- a/flutter_readium_platform_interface/test/models_test.dart
+++ b/flutter_readium_platform_interface/test/models_test.dart
@@ -255,6 +255,29 @@ void main() {
     });
   });
 
+  group('ReadiumTimebasedState', () {
+    test('fromJson normalizes an ended locator with partial location data', () {
+      final state = ReadiumTimebasedState.fromJson({
+        'state': 'ended',
+        'currentLocator': {
+          'href': 'last.mp3',
+          'type': 'audio/mpeg',
+          'locations': {
+            'position': 3,
+            'fragments': ['t=123.45'],
+          },
+        },
+      });
+
+      expect(state.state, TimebasedState.ended);
+      expect(state.currentLocator?.href, 'last.mp3');
+      expect(state.currentLocator?.locations?.position, 3);
+      expect(state.currentLocator?.locations?.fragments, ['t=123.45']);
+      expect(state.currentLocator?.locations?.progression, 1.0);
+      expect(state.currentLocator?.locations?.totalProgression, 1.0);
+    });
+  });
+
   // ---------------------------------------------------------------------------
   // ReadiumReaderStatus enum
   // ---------------------------------------------------------------------------