diff --git a/lib/infrastructure/local/app_database.dart b/lib/infrastructure/local/app_database.dart
index fae882d..05c47a1 100644
--- a/lib/infrastructure/local/app_database.dart
+++ b/lib/infrastructure/local/app_database.dart
@@ -46,7 +46,7 @@ final class AppDatabase extends _$AppDatabase {
   }
 
   @override
-  int get schemaVersion => 12;
+  int get schemaVersion => 13;
 
   @override
   MigrationStrategy get migration {
@@ -97,6 +97,9 @@ final class AppDatabase extends _$AppDatabase {
         if (from < 12) {
           await _migrateToSchema12(migrator);
         }
+        if (from < 13) {
+          await _migrateToSchema13();
+        }
         await _createIndexes();
       },
       beforeOpen: (details) async {
@@ -359,4 +362,111 @@ extension on AppDatabase {
     await migrator.createTable(shareInboxItems);
     await migrator.createTable(pendingShareActions);
   }
+
+  Future<void> _migrateToSchema13() async {
+    await customStatement('PRAGMA foreign_keys = OFF');
+    await customStatement('''
+CREATE TABLE exercises_new (
+  id TEXT NOT NULL PRIMARY KEY,
+  created_at INTEGER NOT NULL,
+  updated_at INTEGER NOT NULL,
+  deleted_at INTEGER,
+  schema_version INTEGER NOT NULL DEFAULT 1,
+  sync_state TEXT NOT NULL CHECK (sync_state IN ('localOnly', 'dirty', 'synced', 'deleted')),
+  local_revision INTEGER NOT NULL CHECK (local_revision >= 0),
+  origin_device_id TEXT NOT NULL,
+  future_owner_profile_id TEXT,
+  last_synced_at INTEGER,
+  remote_revision TEXT,
+  name TEXT NOT NULL,
+  description TEXT,
+  icon_media_id TEXT REFERENCES media_assets(id),
+  video_media_id TEXT REFERENCES media_assets(id),
+  has_time_measure INTEGER NOT NULL CHECK (has_time_measure IN (0, 1)),
+  has_reps_measure INTEGER NOT NULL CHECK (has_reps_measure IN (0, 1)),
+  has_score_measure INTEGER NOT NULL CHECK (has_score_measure IN (0, 1)),
+  score_input_mode TEXT NOT NULL DEFAULT 'manual',
+  score_label TEXT,
+  score_unit TEXT,
+  default_target_time_seconds INTEGER,
+  default_target_reps INTEGER,
+  default_target_score REAL,
+  default_target_score_time_ms INTEGER,
+  archived_at INTEGER,
+  CHECK (length(trim(origin_device_id)) > 0),
+  CHECK (length(trim(name)) > 0),
+  CHECK (has_time_measure OR has_reps_measure OR has_score_measure),
+  CHECK (score_input_mode IN ('manual', 'stopwatch')),
+  CHECK (has_score_measure OR score_input_mode = 'manual'),
+  CHECK (score_input_mode != 'manual' OR NOT has_score_measure OR (score_label IS NOT NULL AND length(trim(score_label)) > 0 AND score_unit IS NOT NULL AND length(trim(score_unit)) > 0)),
+  CHECK (default_target_time_seconds IS NULL OR default_target_time_seconds > 0),
+  CHECK (default_target_reps IS NULL OR default_target_reps > 0),
+  CHECK (default_target_score IS NULL OR default_target_score >= 0),
+  CHECK (default_target_score_time_ms IS NULL OR default_target_score_time_ms > 0),
+  CHECK (future_owner_profile_id IS NULL OR length(trim(future_owner_profile_id)) > 0),
+  CHECK (remote_revision IS NULL OR length(trim(remote_revision)) > 0)
+)
+''');
+    await customStatement('''
+INSERT INTO exercises_new (
+  id,
+  created_at,
+  updated_at,
+  deleted_at,
+  schema_version,
+  sync_state,
+  local_revision,
+  origin_device_id,
+  future_owner_profile_id,
+  last_synced_at,
+  remote_revision,
+  name,
+  description,
+  icon_media_id,
+  video_media_id,
+  has_time_measure,
+  has_reps_measure,
+  has_score_measure,
+  score_input_mode,
+  score_label,
+  score_unit,
+  default_target_time_seconds,
+  default_target_reps,
+  default_target_score,
+  default_target_score_time_ms,
+  archived_at
+)
+SELECT
+  id,
+  created_at,
+  updated_at,
+  deleted_at,
+  schema_version,
+  sync_state,
+  local_revision,
+  origin_device_id,
+  future_owner_profile_id,
+  last_synced_at,
+  remote_revision,
+  name,
+  description,
+  icon_media_id,
+  video_media_id,
+  has_time_measure,
+  has_reps_measure,
+  has_score_measure,
+  score_input_mode,
+  score_label,
+  score_unit,
+  default_target_time_seconds,
+  default_target_reps,
+  default_target_score,
+  default_target_score_time_ms,
+  archived_at
+FROM exercises
+''');
+    await customStatement('DROP TABLE exercises');
+    await customStatement('ALTER TABLE exercises_new RENAME TO exercises');
+    await customStatement('PRAGMA foreign_keys = ON');
+  }
 }
diff --git a/lib/infrastructure/local/tables.dart b/lib/infrastructure/local/tables.dart
index 36d534d..51c2583 100644
--- a/lib/infrastructure/local/tables.dart
+++ b/lib/infrastructure/local/tables.dart
@@ -204,7 +204,7 @@ class Exercises extends SyncableTable {
     'CHECK (default_target_time_seconds IS NULL OR '
         'default_target_time_seconds > 0)',
     'CHECK (default_target_reps IS NULL OR default_target_reps > 0)',
-    'CHECK (default_target_score IS NULL OR default_target_score > 0)',
+    'CHECK (default_target_score IS NULL OR default_target_score >= 0)',
     'CHECK (default_target_score_time_ms IS NULL OR '
         'default_target_score_time_ms > 0)',
   ];
diff --git a/test/infrastructure/drift_repositories_test.dart b/test/infrastructure/drift_repositories_test.dart
index c1b3f2b..ba2925b 100644
--- a/test/infrastructure/drift_repositories_test.dart
+++ b/test/infrastructure/drift_repositories_test.dart
@@ -79,6 +79,25 @@ void main() {
     expect(changes.every((change) => change.entityType == 'Exercise'), isTrue);
   });
 
+  test('exercise repository accepts zero manual default score', () async {
+    final exercise = Exercise(
+      metadata: _metadata('exercise-score-zero', DateTime.utc(2026, 7, 17, 12)),
+      name: 'Score nul',
+      hasTimeMeasure: false,
+      hasRepsMeasure: false,
+      hasScoreMeasure: true,
+      scoreLabel: 'Score',
+      scoreUnit: 'pts',
+      defaultTargetScore: 0,
+    );
+
+    await exerciseRepository.save(exercise);
+
+    final restored = await exerciseRepository.findById(exercise.metadata.id);
+    expect(restored, isNotNull);
+    expect(restored!.defaultTargetScore, 0);
+  });
+
   test('exercise repository round-trips configured steps', () async {
     final now = DateTime.utc(2026, 7, 17, 12);
     final exercise = Exercise(