diff --git a/Package.swift b/Package.swift
index 448343e7b..eb83633c0 100644
--- a/Package.swift
+++ b/Package.swift
@@ -148,7 +148,7 @@ let package = Package(
           ] + wasiLibcCSettings,
           swiftSettings: [
             .enableExperimentalFeature("VariadicGenerics"),
-            .enableExperimentalFeature("Lifetimes"),
+            .enableExperimentalFeature("LifetimeDependence"),
             .enableExperimentalFeature("AddressableTypes"),
             .enableExperimentalFeature("AllowUnsafeAttribute"),
             .enableExperimentalFeature("BuiltinModule"),
diff --git a/Sources/FoundationEssentials/CMakeLists.txt b/Sources/FoundationEssentials/CMakeLists.txt
index 2f04ff0be..8175e009f 100644
--- a/Sources/FoundationEssentials/CMakeLists.txt
+++ b/Sources/FoundationEssentials/CMakeLists.txt
@@ -83,7 +83,7 @@ endif()
 
 target_compile_options(FoundationEssentials PRIVATE
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend VariadicGenerics>"
-    "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend Lifetimes>"
+    "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend LifetimeDependence>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AddressableTypes>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend BuiltinModule>"
     "SHELL:$<$<COMPILE_LANGUAGE:Swift>:-Xfrontend -enable-experimental-feature -Xfrontend AccessLevelOnImport>"
diff --git a/Sources/FoundationEssentials/Data/Data+Reading.swift b/Sources/FoundationEssentials/Data/Data+Reading.swift
index 4dd3714a3..a7421ead4 100644
--- a/Sources/FoundationEssentials/Data/Data+Reading.swift
+++ b/Sources/FoundationEssentials/Data/Data+Reading.swift
@@ -193,7 +193,7 @@ struct ReadBytesResult {
 }
 
 #if os(Windows)
-@_lifetime(pBuffer: copy pBuffer)
+@lifetime(pBuffer: copy pBuffer)
 private func read(from hFile: HANDLE, at path: PathOrURL,
                   into pBuffer: inout OutputRawSpan,
                   chunkSize dwChunk: Int = 4096, progress bProgress: Bool)
diff --git a/Sources/FoundationEssentials/Data/Data.swift b/Sources/FoundationEssentials/Data/Data.swift
index e1cead6ae..ddef89081 100644
--- a/Sources/FoundationEssentials/Data/Data.swift
+++ b/Sources/FoundationEssentials/Data/Data.swift
@@ -353,7 +353,7 @@ public struct Data : RandomAccessCollection, MutableCollection, RangeReplaceable
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var bytes: RawSpan {
-        @_lifetime(borrow self)
+        @lifetime(borrow self)
         borrowing get {
             let buffer: UnsafeRawBufferPointer
             switch _representation {
@@ -381,7 +381,7 @@ public struct Data : RandomAccessCollection, MutableCollection, RangeReplaceable
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var span: Span<UInt8> {
-        @_lifetime(borrow self)
+        @lifetime(borrow self)
         borrowing get {
             let span = unsafe bytes._unsafeView(as: UInt8.self)
             return _overrideLifetime(span, borrowing: self)
@@ -391,7 +391,7 @@ public struct Data : RandomAccessCollection, MutableCollection, RangeReplaceable
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var mutableBytes: MutableRawSpan {
-        @_lifetime(&self)
+        @lifetime(&self)
         mutating get {
             let buffer: UnsafeMutableRawBufferPointer
             switch _representation {
@@ -427,7 +427,7 @@ public struct Data : RandomAccessCollection, MutableCollection, RangeReplaceable
     @available(macOS 10.14.4, iOS 12.2, watchOS 5.2, tvOS 12.2, *)
     @_alwaysEmitIntoClient
     public var mutableSpan: MutableSpan<UInt8> {
-        @_lifetime(&self)
+        @lifetime(&self)
         mutating get {
 #if false // see https://github.com/swiftlang/swift/issues/81218
             var bytes = mutableBytes