diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c9ed2bb..b8990e2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,9 +26,9 @@ jobs:
     strategy:
       matrix:
         tag:
-          - swift:5.5
           - swift:5.6
           - swift:5.7
+          - swift:5.8
     container:
       image: ${{ matrix.tag }}
     steps:
diff --git a/Package@swift-5.4.swift b/Package@swift-5.4.swift
deleted file mode 100644
index 13102aa..0000000
--- a/Package@swift-5.4.swift
+++ /dev/null
@@ -1,39 +0,0 @@
-// swift-tools-version:5.4
-import PackageDescription
-
-let package = Package(
-    name: "soto-codegenerator",
-    products: [
-        .executable(name: "SotoCodeGenerator", targets: ["SotoCodeGenerator"]),
-        .library(name: "SotoCodeGeneratorLib", targets: ["SotoCodeGeneratorLib"])
-    ],
-    dependencies: [
-        .package(url: "https://github.com/soto-project/soto-smithy.git", from: "0.3.1"),
-        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.0.0"),
-        .package(url: "https://github.com/hummingbird-project/hummingbird-mustache.git", from: "1.0.3"),
-        .package(url: "https://github.com/apple/swift-log.git", from: "1.4.0"),
-    ],
-    targets: [
-        .executableTarget(
-            name: "SotoCodeGenerator",
-            dependencies: [
-                .byName(name: "SotoCodeGeneratorLib"),
-                .product(name: "ArgumentParser", package: "swift-argument-parser"),
-                .product(name: "Logging", package: "swift-log")
-            ]
-        ),
-        .target(
-            name: "SotoCodeGeneratorLib",
-            dependencies: [
-                .product(name: "SotoSmithy", package: "soto-smithy"),
-                .product(name: "SotoSmithyAWS", package: "soto-smithy"),
-                .product(name: "HummingbirdMustache", package: "hummingbird-mustache"),
-                .product(name: "Logging", package: "swift-log")
-            ]
-        ),
-        .testTarget(
-            name: "SotoCodeGeneratorTests",
-            dependencies: [.byName(name: "SotoCodeGeneratorLib")]
-        )
-    ]
-)
diff --git a/Package@swift-5.5.swift b/Package@swift-5.5.swift
deleted file mode 100644
index 2b4ba45..0000000
--- a/Package@swift-5.5.swift
+++ /dev/null
@@ -1,39 +0,0 @@
-// swift-tools-version:5.5
-import PackageDescription
-
-let package = Package(
-    name: "soto-codegenerator",
-    products: [
-        .executable(name: "SotoCodeGenerator", targets: ["SotoCodeGenerator"]),
-        .library(name: "SotoCodeGeneratorLib", targets: ["SotoCodeGeneratorLib"])
-    ],
-    dependencies: [
-        .package(url: "https://github.com/soto-project/soto-smithy.git", from: "0.3.1"),
-        .package(url: "https://github.com/apple/swift-argument-parser.git", from: "1.0.0"),
-        .package(url: "https://github.com/hummingbird-project/hummingbird-mustache.git", from: "1.0.3"),
-        .package(url: "https://github.com/apple/swift-log.git", from: "1.4.0"),
-    ],
-    targets: [
-        .executableTarget(
-            name: "SotoCodeGenerator",
-            dependencies: [
-                .byName(name: "SotoCodeGeneratorLib"),
-                .product(name: "ArgumentParser", package: "swift-argument-parser"),
-                .product(name: "Logging", package: "swift-log")
-            ]
-        ),
-        .target(
-            name: "SotoCodeGeneratorLib",
-            dependencies: [
-                .product(name: "SotoSmithy", package: "soto-smithy"),
-                .product(name: "SotoSmithyAWS", package: "soto-smithy"),
-                .product(name: "HummingbirdMustache", package: "hummingbird-mustache"),
-                .product(name: "Logging", package: "swift-log")
-            ]
-        ),
-        .testTarget(
-            name: "SotoCodeGeneratorTests",
-            dependencies: [.byName(name: "SotoCodeGeneratorLib")]
-        )
-    ]
-)
diff --git a/Sources/SotoCodeGeneratorLib/Templates/api+async.swift b/Sources/SotoCodeGeneratorLib/Templates/api+async.swift
index 067c3a1..b483957 100644
--- a/Sources/SotoCodeGeneratorLib/Templates/api+async.swift
+++ b/Sources/SotoCodeGeneratorLib/Templates/api+async.swift
@@ -17,8 +17,6 @@ extension Templates {
     {{%CONTENT_TYPE:TEXT}}
     {{>header}}
 
-    #if compiler(>=5.5.2) && canImport(_Concurrency)
-
     import SotoCore
 
     @available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
@@ -68,7 +66,5 @@ extension Templates {
     {{>waiters_async}}
     {{/waiters}}
 
-    #endif // compiler(>=5.5.2) && canImport(_Concurrency)
-
     """
 }
diff --git a/Sources/SotoCodeGeneratorLib/Templates/enum.swift b/Sources/SotoCodeGeneratorLib/Templates/enum.swift
index 5364c54..ba8231d 100644
--- a/Sources/SotoCodeGeneratorLib/Templates/enum.swift
+++ b/Sources/SotoCodeGeneratorLib/Templates/enum.swift
@@ -16,7 +16,7 @@ extension Templates {
     static let enumTemplate = """
     {{%CONTENT_TYPE:TEXT}}
     {{#isExtensible}}
-        {{scope}} struct {{name}}: RawRepresentable, Equatable, Codable, _SotoSendable {
+        {{scope}} struct {{name}}: RawRepresentable, Equatable, Codable, Sendable {
             {{scope}} var rawValue: String
 
             {{scope}} init(rawValue: String) {
@@ -32,7 +32,7 @@ extension Templates {
         }
     {{/isExtensible}}
     {{^isExtensible}}
-        {{scope}} enum {{name}}: String, CustomStringConvertible, Codable, _SotoSendable {
+        {{scope}} enum {{name}}: String, CustomStringConvertible, Codable, Sendable {
     {{#values}}
     {{#documentation}}
             {{>comment}}
diff --git a/Sources/SotoCodeGeneratorLib/Templates/enumWithValues.swift b/Sources/SotoCodeGeneratorLib/Templates/enumWithValues.swift
index a452360..776327c 100644
--- a/Sources/SotoCodeGeneratorLib/Templates/enumWithValues.swift
+++ b/Sources/SotoCodeGeneratorLib/Templates/enumWithValues.swift
@@ -16,7 +16,7 @@ extension Templates {
     static let enumWithValuesTemplate = #"""
     {{! Template for a AWSShape enum with values }}
     {{%CONTENT_TYPE:TEXT}}
-        {{scope}} {{object}} {{name}}: {{shapeProtocol}}, _SotoSendable {
+        {{scope}} {{object}} {{name}}: {{shapeProtocol}}, Sendable {
     {{#namespace}}
             {{scope}} static let _xmlNamespace: String? = "{{.}}"
     {{/namespace}}