diff --git a/Package.swift b/Package.swift
index 923815f..1c08bf9 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.6
+// swift-tools-version:5.7
 
 import PackageDescription
 
diff --git a/Sources/AWSLambdaEvents/Cloudwatch.swift b/Sources/AWSLambdaEvents/Cloudwatch.swift
index a6441c6..e27af01 100644
--- a/Sources/AWSLambdaEvents/Cloudwatch.swift
+++ b/Sources/AWSLambdaEvents/Cloudwatch.swift
@@ -12,10 +12,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=5.6)
-@preconcurrency import struct Foundation.Date
-#else
+#if canImport(Darwin)
 import struct Foundation.Date
+#else
+@preconcurrency import struct Foundation.Date
 #endif
 
 /// EventBridge has the same events/notification types as CloudWatch
diff --git a/Sources/AWSLambdaEvents/DynamoDB.swift b/Sources/AWSLambdaEvents/DynamoDB.swift
index c0f1000..71ff22e 100644
--- a/Sources/AWSLambdaEvents/DynamoDB.swift
+++ b/Sources/AWSLambdaEvents/DynamoDB.swift
@@ -12,10 +12,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=5.6)
-@preconcurrency import struct Foundation.Date
-#else
+#if canImport(Darwin)
 import struct Foundation.Date
+#else
+@preconcurrency import struct Foundation.Date
 #endif
 
 // https://docs.aws.amazon.com/lambda/latest/dg/with-ddb.html
diff --git a/Sources/AWSLambdaEvents/Utils/DateWrappers.swift b/Sources/AWSLambdaEvents/Utils/DateWrappers.swift
index eedcf23..235e380 100644
--- a/Sources/AWSLambdaEvents/Utils/DateWrappers.swift
+++ b/Sources/AWSLambdaEvents/Utils/DateWrappers.swift
@@ -12,10 +12,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#if swift(>=5.6)
-@preconcurrency import struct Foundation.Date
-#else
+#if canImport(Darwin)
 import struct Foundation.Date
+#else
+@preconcurrency import struct Foundation.Date
 #endif
 import class Foundation.DateFormatter
 import struct Foundation.Locale
diff --git a/docker/docker-compose.al2.54.yaml b/docker/docker-compose.al2.54.yaml
deleted file mode 100644
index c23061c..0000000
--- a/docker/docker-compose.al2.54.yaml
+++ /dev/null
@@ -1,18 +0,0 @@
-version: "3"
-
-services:
-
-  runtime-setup:
-    image: swift-aws-lambda-events:al2-5.4
-    build:
-      args:
-        swift_version: "5.4"
-
-  test:
-    image: swift-aws-lambda-events:al2-5.4
-
-  test-samples:
-    image: swift-aws-lambda-events:al2-5.4
-
-  shell:
-    image: swift-aws-lambda-events:al2-5.4
diff --git a/docker/docker-compose.al2.55.yaml b/docker/docker-compose.al2.55.yaml
deleted file mode 100644
index fc05473..0000000
--- a/docker/docker-compose.al2.55.yaml
+++ /dev/null
@@ -1,18 +0,0 @@
-version: "3"
-
-services:
-
-  runtime-setup:
-    image: swift-aws-lambda-events:al2-5.5
-    build:
-      args:
-        swift_version: "5.5"
-
-  test:
-    image: swift-aws-lambda-events:al2-5.5
-
-  test-samples:
-    image: swift-aws-lambda-events:al2-5.5
-
-  shell:
-    image: swift-aws-lambda-events:al2-5.5
diff --git a/docker/docker-compose.al2.57.yaml b/docker/docker-compose.al2.57.yaml
index 45805c9..17c650a 100644
--- a/docker/docker-compose.al2.57.yaml
+++ b/docker/docker-compose.al2.57.yaml
@@ -6,7 +6,7 @@ services:
     image: swift-aws-lambda-events:al2-5.7
     build:
       args:
-        base_image: "swiftlang/swift:nightly-main-amazonlinux2"
+        swift_version: "5.7"
 
   test:
     image: swift-aws-lambda-events:al2-5.7
diff --git a/docker/docker-compose.yaml b/docker/docker-compose.yaml
index e7fba40..e194a58 100644
--- a/docker/docker-compose.yaml
+++ b/docker/docker-compose.yaml
@@ -1,6 +1,6 @@
 # this file is not designed to be run directly
 # instead, use the docker-compose.<os>.<swift> files
-# eg docker-compose -f docker/docker-compose.yaml -f docker/docker-compose.al2.52.yaml run test
+# eg docker-compose -f docker/docker-compose.yaml -f docker/docker-compose.al2.57.yaml run test
 version: "3"
 
 services: