diff --git a/Package.swift b/Package.swift
index 3344d624..689e6c83 100644
--- a/Package.swift
+++ b/Package.swift
@@ -1,4 +1,4 @@
-// swift-tools-version:5.8
+// swift-tools-version:5.9
 //===----------------------------------------------------------------------===//
 //
 // This source file is part of the SwiftCrypto open source project
diff --git a/README.md b/README.md
index daec8aa6..9a72b1c3 100644
--- a/README.md
+++ b/README.md
@@ -117,7 +117,8 @@ Swift Crypto      | Minimum Swift Version
 `2.2.0 ..< 2.4.2` | 5.5
 `2.4.2 ..< 3.1.0` | 5.6
 `3.1.0 ..< 3.3.0` | 5.7
-`3.3.0 ...`       | 5.8
+`3.3.0 ..< 3.8.0` | 5.8
+`3.8.0 ...`       | 5.9
 
 ### Compatibility
 
diff --git a/Sources/_CryptoExtras/AES/AES_GCM_SIV.swift b/Sources/_CryptoExtras/AES/AES_GCM_SIV.swift
index 527a91a3..7cddcf1b 100644
--- a/Sources/_CryptoExtras/AES/AES_GCM_SIV.swift
+++ b/Sources/_CryptoExtras/AES/AES_GCM_SIV.swift
@@ -16,11 +16,7 @@ import Crypto
 @_implementationOnly import CCryptoBoringSSL
 @_implementationOnly import CCryptoBoringSSLShims
 @_implementationOnly import CryptoBoringWrapper
-#if canImport(Darwin) || swift(>=5.9.1)
 import Foundation
-#else
-@preconcurrency import Foundation
-#endif
 
 /// Types associated with the AES GCM SIV algorithm
 extension AES.GCM {
diff --git a/Sources/_CryptoExtras/ChaCha20CTR/ChaCha20CTR.swift b/Sources/_CryptoExtras/ChaCha20CTR/ChaCha20CTR.swift
index 975010ae..1dea4969 100644
--- a/Sources/_CryptoExtras/ChaCha20CTR/ChaCha20CTR.swift
+++ b/Sources/_CryptoExtras/ChaCha20CTR/ChaCha20CTR.swift
@@ -16,11 +16,7 @@
 @_implementationOnly import CCryptoBoringSSLShims
 import Crypto
 @_implementationOnly import CryptoBoringWrapper
-#if canImport(Darwin) || swift(>=5.9.1)
 import Foundation
-#else
-@preconcurrency import Foundation
-#endif
 
 typealias ChaCha20CTRImpl = OpenSSLChaCha20CTRImpl
 
diff --git a/Sources/_CryptoExtras/RSA/RSA.swift b/Sources/_CryptoExtras/RSA/RSA.swift
index 6177d0c8..00b98e86 100644
--- a/Sources/_CryptoExtras/RSA/RSA.swift
+++ b/Sources/_CryptoExtras/RSA/RSA.swift
@@ -31,12 +31,8 @@ fileprivate typealias BackingPrivateKey = BoringSSLRSAPrivateKey
 ///
 /// When rolling out new cryptosystems, users should avoid RSA and use ECDSA or edDSA instead. RSA
 /// support is provided for interoperability with legacy systems.
-#if swift(>=5.8)
 @_documentation(visibility: public)
 public enum _RSA { }
-#else
-public enum _RSA { }
-#endif
 
 extension _RSA {
     public enum Signing { }
diff --git a/docker/docker-compose.2204.58.yaml b/docker/docker-compose.2204.58.yaml
deleted file mode 100644
index 48846020..00000000
--- a/docker/docker-compose.2204.58.yaml
+++ /dev/null
@@ -1,21 +0,0 @@
-version: "3"
-
-services:
-
-  runtime-setup:
-    image: swift-crypto:22.04-5.8
-    build:
-      args:
-        ubuntu_version: "jammy"
-        swift_version: "5.8"
-
-  test:
-    image: swift-crypto:22.04-5.8
-    environment: []
-      #- SANITIZER_ARG=--sanitize=thread
-
-  cmake:
-    image: swift-crypto:22.04-5.8
-
-  shell:
-    image: swift-crypto:22.04-5.8