diff --git a/bin/internal/flutter.version b/bin/internal/flutter.version
index 142383be..15d6a4ed 100644
--- a/bin/internal/flutter.version
+++ b/bin/internal/flutter.version
@@ -1 +1 @@
-cd234ef8ece6e82da6bec9b9d811e818e8d8373a
+c5176e1323bd85e34758ae546d6f2b8003d3109c
diff --git a/packages/shorebird_cli/lib/src/commands/release/releaser.dart b/packages/shorebird_cli/lib/src/commands/release/releaser.dart
index 2fc4b3b6..d48eae2b 100644
--- a/packages/shorebird_cli/lib/src/commands/release/releaser.dart
+++ b/packages/shorebird_cli/lib/src/commands/release/releaser.dart
@@ -153,11 +153,30 @@ abstract class Releaser {
       platformSubdir: supplementPlatformSubdir,
       create: hasObfuscationMap,
     );
-    if (hasObfuscationMap && supplementDir != null) {
-      obfuscationMapFile.copySync(
-        p.join(supplementDir.path, 'obfuscation_map.json'),
+    if (supplementDir == null) return null;
+
+    final targetMapFile = File(
+      p.join(supplementDir.path, 'obfuscation_map.json'),
+    );
+    if (hasObfuscationMap) {
+      obfuscationMapFile.copySync(targetMapFile.path);
+    } else if (targetMapFile.existsSync()) {
+      // Remove stale obfuscation map from a previous obfuscated build so that
+      // the supplement doesn't incorrectly signal that this release was
+      // obfuscated.
+      logger.detail(
+        'Removing stale obfuscation map from supplement directory. '
+        'If this release should be obfuscated, re-run with --obfuscate.',
       );
+      targetMapFile.deleteSync();
     }
+
+    // Return null if the supplement directory is now empty (nothing to upload).
+    // Note: currently the obfuscation map is the only supplement artifact. If
+    // other supplement files are added in the future, this check (and the
+    // stale-file cleanup above) should be updated to handle them explicitly.
+    if (supplementDir.listSync().isEmpty) return null;
+
     return supplementDir;
   }
 
diff --git a/packages/shorebird_cli/test/src/commands/release/aar_releaser_test.dart b/packages/shorebird_cli/test/src/commands/release/aar_releaser_test.dart
index 2867e377..e73b9655 100644
--- a/packages/shorebird_cli/test/src/commands/release/aar_releaser_test.dart
+++ b/packages/shorebird_cli/test/src/commands/release/aar_releaser_test.dart
@@ -562,6 +562,121 @@ void main() {
       });
     });
 
+    group('assembleSupplementDirectory', () {
+      late Directory supplementDir;
+
+      setUp(() {
+        // Create the supplement directory as it would exist on disk.
+        supplementDir = Directory(
+          p.join(projectRoot.path, 'build', 'android', 'shorebird'),
+        )..createSync(recursive: true);
+
+        // Stub getReleaseSupplementDirectory to use the real directory.
+        when(
+          () => artifactManager.getReleaseSupplementDirectory(
+            platformSubdir: any(named: 'platformSubdir'),
+            create: any(named: 'create'),
+          ),
+        ).thenAnswer((invocation) {
+          final create =
+              invocation.namedArguments[const Symbol('create')] as bool;
+          if (!supplementDir.existsSync() && create) {
+            supplementDir.createSync(recursive: true);
+          }
+          return supplementDir.existsSync() ? supplementDir : null;
+        });
+      });
+
+      group('when obfuscation is enabled and map exists', () {
+        setUp(() {
+          when(() => argResults['obfuscate']).thenReturn(true);
+          when(() => argResults.wasParsed('obfuscate')).thenReturn(true);
+
+          // Create the obfuscation map at the expected build output location.
+          final mapFile = File(
+            p.join(
+              projectRoot.path,
+              'build',
+              'shorebird',
+              'obfuscation_map.json',
+            ),
+          )..createSync(recursive: true);
+          mapFile.writeAsStringSync('{"key": "value"}');
+        });
+
+        test('copies map into supplement directory and returns it', () {
+          final result = runWithOverrides(
+            () => aarReleaser.assembleSupplementDirectory(),
+          );
+
+          expect(result, isNotNull);
+          final mapInSupplement = File(
+            p.join(supplementDir.path, 'obfuscation_map.json'),
+          );
+          expect(mapInSupplement.existsSync(), isTrue);
+          expect(mapInSupplement.readAsStringSync(), '{"key": "value"}');
+        });
+      });
+
+      group('when obfuscation is disabled', () {
+        setUp(() {
+          when(() => argResults['obfuscate']).thenReturn(false);
+        });
+
+        group('and no stale map exists', () {
+          test('returns null', () {
+            // Remove the supplement dir so it's empty/missing.
+            if (supplementDir.existsSync()) {
+              supplementDir.deleteSync(recursive: true);
+            }
+            when(
+              () => artifactManager.getReleaseSupplementDirectory(
+                platformSubdir: any(named: 'platformSubdir'),
+                create: any(named: 'create'),
+              ),
+            ).thenReturn(null);
+
+            final result = runWithOverrides(
+              () => aarReleaser.assembleSupplementDirectory(),
+            );
+
+            expect(result, isNull);
+          });
+        });
+
+        group('and a stale obfuscation map exists', () {
+          setUp(() {
+            // Simulate a leftover obfuscation_map.json from a previous
+            // obfuscated build.
+            File(
+                p.join(supplementDir.path, 'obfuscation_map.json'),
+              )
+              ..createSync(recursive: true)
+              ..writeAsStringSync('{"stale": true}');
+          });
+
+          test('removes stale map, logs detail, and returns null', () {
+            final result = runWithOverrides(
+              () => aarReleaser.assembleSupplementDirectory(),
+            );
+
+            expect(result, isNull);
+            expect(
+              File(
+                p.join(supplementDir.path, 'obfuscation_map.json'),
+              ).existsSync(),
+              isFalse,
+            );
+            verify(
+              () => logger.detail(
+                any(that: contains('Removing stale obfuscation map')),
+              ),
+            ).called(1);
+          });
+        });
+      });
+    });
+
     group('getReleaseVersion', () {
       const releaseVersion = '1.0.0';
       setUp(() {