diff --git a/script/tool/lib/src/native_test_command.dart b/script/tool/lib/src/native_test_command.dart
index f3fd2b7f6c92..20eef521de22 100644
--- a/script/tool/lib/src/native_test_command.dart
+++ b/script/tool/lib/src/native_test_command.dart
@@ -465,7 +465,9 @@ this command.
       _printRunningExampleTestsMessage(example, platform);
       final int exitCode = await _xcode.runXcodeBuild(
         example.directory,
-        actions: <String>['test'],
+        // Clean before testing to remove cached swiftmodules from previous
+        // runs, which can cause conflicts.
+        actions: <String>['clean', 'test'],
         workspace: '${platform.toLowerCase()}/Runner.xcworkspace',
         scheme: 'Runner',
         configuration: 'Debug',
diff --git a/script/tool/lib/src/xcode_analyze_command.dart b/script/tool/lib/src/xcode_analyze_command.dart
index e753ccb21fc0..6760eeeff8ef 100644
--- a/script/tool/lib/src/xcode_analyze_command.dart
+++ b/script/tool/lib/src/xcode_analyze_command.dart
@@ -111,7 +111,9 @@ class XcodeAnalyzeCommand extends PackageLoopingCommand {
       print('Running $platform tests and analyzer for $examplePath...');
       final int exitCode = await _xcode.runXcodeBuild(
         example.directory,
-        actions: <String>['analyze'],
+        // Clean before analyzing to remove cached swiftmodules from previous
+        // runs, which can cause conflicts.
+        actions: <String>['clean', 'analyze'],
         workspace: '${platform.toLowerCase()}/Runner.xcworkspace',
         scheme: 'Runner',
         configuration: 'Debug',
diff --git a/script/tool/test/native_test_command_test.dart b/script/tool/test/native_test_command_test.dart
index 993ee86d600c..cd3569739e22 100644
--- a/script/tool/test/native_test_command_test.dart
+++ b/script/tool/test/native_test_command_test.dart
@@ -139,6 +139,7 @@ void main() {
           'xcrun',
           <String>[
             'xcodebuild',
+            'clean',
             'test',
             '-workspace',
             '$platform/Runner.xcworkspace',
@@ -220,7 +221,7 @@ void main() {
         getMockXcodebuildListProcess(<String>['RunnerTests', 'RunnerUITests']),
         // Exit code 66 from testing indicates no tests.
         FakeProcessInfo(
-            MockProcess(exitCode: 66), <String>['xcodebuild', 'test']),
+            MockProcess(exitCode: 66), <String>['xcodebuild', 'clean', 'test']),
       ];
       final List<String> output = await runCapturingPrint(
           runner, <String>['native-test', '--macos', '--no-unit']);
@@ -1469,11 +1470,11 @@ public class FlutterActivityTest {
           getMockXcodebuildListProcess(
               <String>['RunnerTests', 'RunnerUITests']), // iOS list
           FakeProcessInfo(
-              MockProcess(), <String>['xcodebuild', 'test']), // iOS run
+              MockProcess(), <String>['xcodebuild', 'clean', 'test']), // iOS run
           getMockXcodebuildListProcess(
               <String>['RunnerTests', 'RunnerUITests']), // macOS list
           FakeProcessInfo(
-              MockProcess(), <String>['xcodebuild', 'test']), // macOS run
+              MockProcess(), <String>['xcodebuild', 'clean', 'test']), // macOS run
         ];
 
         final List<String> output = await runCapturingPrint(runner, <String>[
diff --git a/script/tool/test/xcode_analyze_command_test.dart b/script/tool/test/xcode_analyze_command_test.dart
index 2caf906fc6a5..cd4fb7306c47 100644
--- a/script/tool/test/xcode_analyze_command_test.dart
+++ b/script/tool/test/xcode_analyze_command_test.dart
@@ -106,6 +106,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'ios/Runner.xcworkspace',
@@ -146,6 +147,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'ios/Runner.xcworkspace',
@@ -244,6 +246,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'macos/Runner.xcworkspace',
@@ -278,6 +281,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'macos/Runner.xcworkspace',
@@ -350,6 +354,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'ios/Runner.xcworkspace',
@@ -366,6 +371,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'macos/Runner.xcworkspace',
@@ -406,6 +412,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'macos/Runner.xcworkspace',
@@ -445,6 +452,7 @@ void main() {
                   'xcrun',
                   const <String>[
                     'xcodebuild',
+                    'clean',
                     'analyze',
                     '-workspace',
                     'ios/Runner.xcworkspace',