diff --git a/Package.swift b/Package.swift
index 5567d18c2..1ca2a7400 100644
--- a/Package.swift
+++ b/Package.swift
@@ -74,6 +74,7 @@ let package = Package(
         .target(
             name: "_RegexParser",
             dependencies: [],
+            packageAccess: false,
             swiftSettings: privateStdlibSettings),
         .testTarget(
             name: "MatchingEngineTests",
@@ -89,10 +90,12 @@ let package = Package(
               "_RegexParser",
               "_CUnicode",
             ],
+            packageAccess: false,
             swiftSettings: publicStdlibSettings),
         .target(
             name: "RegexBuilder",
             dependencies: ["_StringProcessing", "_RegexParser"],
+            packageAccess: false,
             swiftSettings: publicStdlibSettings),
         .target(name: "TestSupport",
                 swiftSettings: [availabilityDefinition]),
diff --git a/Sources/RegexBuilder/DSL.swift b/Sources/RegexBuilder/DSL.swift
index 7e19caae2..42266466f 100644
--- a/Sources/RegexBuilder/DSL.swift
+++ b/Sources/RegexBuilder/DSL.swift
@@ -32,21 +32,21 @@ internal protocol _BuiltinRegexComponent: RegexComponent {
 // MARK: - Primitive regex components
 
 @available(SwiftStdlib 5.7, *)
-extension String: RegexComponent {
+extension String: @retroactive RegexComponent {
   public typealias Output = Substring
 
   public var regex: Regex<Output> { .init(verbatim: self) }
 }
 
 @available(SwiftStdlib 5.7, *)
-extension Substring: RegexComponent {
+extension Substring: @retroactive RegexComponent {
   public typealias Output = Substring
 
   public var regex: Regex<Output> { String(self).regex }
 }
 
 @available(SwiftStdlib 5.7, *)
-extension Character: RegexComponent {
+extension Character: @retroactive RegexComponent {
   public typealias Output = Substring
 
   public var regex: Regex<Output> {
@@ -55,7 +55,7 @@ extension Character: RegexComponent {
 }
 
 @available(SwiftStdlib 5.7, *)
-extension UnicodeScalar: RegexComponent {
+extension UnicodeScalar: @retroactive RegexComponent {
   public typealias Output = Substring
 
   public var regex: Regex<Output> {