diff --git a/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/ec2query/Ec2QueryHttpResponseBindingErrorGeneratorTests.kt b/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/ec2query/Ec2QueryHttpResponseBindingErrorGeneratorTests.kt
index 29d37341456..7da84ec1e7b 100644
--- a/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/ec2query/Ec2QueryHttpResponseBindingErrorGeneratorTests.kt
+++ b/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/ec2query/Ec2QueryHttpResponseBindingErrorGeneratorTests.kt
@@ -69,9 +69,9 @@ extension ComplexError {
         val contents = TestUtils.getFileContents(context.manifest, "Sources/Example/models/ComplexError.swift")
         contents.shouldSyntacticSanityCheck()
         val expectedContents = """
-public struct ComplexError: ClientRuntime.ModeledError, AWSClientRuntime.AWSServiceError, ClientRuntime.HTTPError, Swift.Error {
+public struct ComplexError: ClientRuntime.ModeledError, AWSClientRuntime.AWSServiceError, ClientRuntime.HTTPError, Swift.Error, Swift.Sendable {
 
-    public struct Properties {
+    public struct Properties: Swift.Sendable {
         public internal(set) var nested: EC2ProtocolClientTypes.ComplexNestedErrorData? = nil
         public internal(set) var topLevel: Swift.String? = nil
     }
diff --git a/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/restxml/AWSRestXMLHTTPResponseBindingErrorGeneratorTests.kt b/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/restxml/AWSRestXMLHTTPResponseBindingErrorGeneratorTests.kt
index b1a639969cc..4dedf51d6c5 100644
--- a/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/restxml/AWSRestXMLHTTPResponseBindingErrorGeneratorTests.kt
+++ b/codegen/smithy-aws-swift-codegen/src/test/kotlin/software/amazon/smithy/aws/swift/codegen/restxml/AWSRestXMLHTTPResponseBindingErrorGeneratorTests.kt
@@ -72,9 +72,9 @@ extension ComplexXMLError {
         val contents = getFileContents(context.manifest, "/Sources/Example/models/ComplexXMLError.swift")
         contents.shouldSyntacticSanityCheck()
         val expectedContents = """
-public struct ComplexXMLError: ClientRuntime.ModeledError, AWSClientRuntime.AWSServiceError, ClientRuntime.HTTPError, Swift.Error {
+public struct ComplexXMLError: ClientRuntime.ModeledError, AWSClientRuntime.AWSServiceError, ClientRuntime.HTTPError, Swift.Error, Swift.Sendable {
 
-    public struct Properties {
+    public struct Properties: Swift.Sendable {
         public internal(set) var header: Swift.String? = nil
         public internal(set) var nested: RestXmlerrorsClientTypes.ComplexXMLNestedErrorData? = nil
         public internal(set) var topLevel: Swift.String? = nil