diff --git a/Package.swift b/Package.swift
index a82241527..d37754a1a 100644
--- a/Package.swift
+++ b/Package.swift
@@ -385,11 +385,6 @@ extension Array where Element == PackageDescription.SwiftSetting {
 
       .enableUpcomingFeature("MemberImportVisibility"),
 
-      // This setting is enabled in the package, but not in the toolchain build
-      // (via CMake). Enabling it is dependent on acceptance of the @section
-      // proposal via Swift Evolution.
-      .enableExperimentalFeature("SymbolLinkageMarkers"),
-
       .enableUpcomingFeature("InferIsolatedConformances"),
 
       // When building as a package, the macro plugin always builds as an
@@ -410,6 +405,21 @@ extension Array where Element == PackageDescription.SwiftSetting {
       .define("SWT_NO_LIBDISPATCH", .whenEmbedded()),
     ]
 
+#if compiler(>=6.3)
+#if !SWT_FIXED_85411
+    // Work around https://github.com/swiftlang/swift/issues/85411
+    result += [
+      .enableExperimentalFeature("CompileTimeValuesPreview"),
+    ]
+#endif
+#else
+    // This setting is enabled in the package, but not in the toolchain build
+    // (via CMake). The @section attribute is formally supported in Swift 6.3.
+    result += [
+      .enableExperimentalFeature("SymbolLinkageMarkers"),
+    ]
+#endif
+
     return result
   }
 
diff --git a/Sources/TestingMacros/ConditionMacro.swift b/Sources/TestingMacros/ConditionMacro.swift
index 6ba8ff124..2c3d16cbe 100644
--- a/Sources/TestingMacros/ConditionMacro.swift
+++ b/Sources/TestingMacros/ConditionMacro.swift
@@ -13,8 +13,8 @@ public import SwiftSyntax
 import SwiftSyntaxBuilder
 public import SwiftSyntaxMacros
 
-#if !hasFeature(SymbolLinkageMarkers) && SWT_NO_LEGACY_TEST_DISCOVERY
-#error("Platform-specific misconfiguration: either SymbolLinkageMarkers or legacy test discovery is required to expand #expect(processExitsWith:)")
+#if !((compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)) || hasFeature(SymbolLinkageMarkers)) && SWT_NO_LEGACY_TEST_DISCOVERY
+#error("Platform-specific misconfiguration: either CompileTimeValuesPreview, SymbolLinkageMarkers, or legacy test discovery is required to expand #expect(processExitsWith:)")
 #endif
 
 /// A protocol containing the common implementation for the expansions of the
diff --git a/Sources/TestingMacros/SuiteDeclarationMacro.swift b/Sources/TestingMacros/SuiteDeclarationMacro.swift
index 4bee4c30f..80458c04f 100644
--- a/Sources/TestingMacros/SuiteDeclarationMacro.swift
+++ b/Sources/TestingMacros/SuiteDeclarationMacro.swift
@@ -13,8 +13,8 @@ public import SwiftSyntax
 import SwiftSyntaxBuilder
 public import SwiftSyntaxMacros
 
-#if !hasFeature(SymbolLinkageMarkers) && SWT_NO_LEGACY_TEST_DISCOVERY
-#error("Platform-specific misconfiguration: either SymbolLinkageMarkers or legacy test discovery is required to expand @Suite")
+#if !((compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)) || hasFeature(SymbolLinkageMarkers)) && SWT_NO_LEGACY_TEST_DISCOVERY
+#error("Platform-specific misconfiguration: either CompileTimeValuesPreview, SymbolLinkageMarkers, or legacy test discovery is required to expand @Suite")
 #endif
 
 /// A type describing the expansion of the `@Suite` attribute macro.
diff --git a/Sources/TestingMacros/Support/TestContentGeneration.swift b/Sources/TestingMacros/Support/TestContentGeneration.swift
index 05214d1b8..90471cf8b 100644
--- a/Sources/TestingMacros/Support/TestContentGeneration.swift
+++ b/Sources/TestingMacros/Support/TestContentGeneration.swift
@@ -74,7 +74,23 @@ func makeTestContentRecordDecl(named name: TokenSyntax, in typeName: TypeSyntax?
   )
   """
 
-#if hasFeature(SymbolLinkageMarkers)
+#if compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)
+  result = """
+  #if compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)
+  #if objectFormat(MachO)
+  @section("__DATA_CONST,__swift5_tests")
+  #elseif objectFormat(ELF) || objectFormat(Wasm)
+  @section("swift5_tests")
+  #elseif objectFormat(COFF)
+  @section(".sw5test$B")
+  #else
+  @Testing.__testing(warning: "Platform-specific implementation missing: object format unknown")
+  #endif
+  @used
+  #endif
+  \(result)
+  """
+#elseif hasFeature(SymbolLinkageMarkers)
   result = """
   #if hasFeature(SymbolLinkageMarkers)
   #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || os(visionOS)
diff --git a/Sources/TestingMacros/TestDeclarationMacro.swift b/Sources/TestingMacros/TestDeclarationMacro.swift
index 8007c3aaf..77f4b1b5a 100644
--- a/Sources/TestingMacros/TestDeclarationMacro.swift
+++ b/Sources/TestingMacros/TestDeclarationMacro.swift
@@ -13,8 +13,8 @@ public import SwiftSyntax
 import SwiftSyntaxBuilder
 public import SwiftSyntaxMacros
 
-#if !hasFeature(SymbolLinkageMarkers) && SWT_NO_LEGACY_TEST_DISCOVERY
-#error("Platform-specific misconfiguration: either SymbolLinkageMarkers or legacy test discovery is required to expand @Test")
+#if !((compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)) || hasFeature(SymbolLinkageMarkers)) && SWT_NO_LEGACY_TEST_DISCOVERY
+#error("Platform-specific misconfiguration: either CompileTimeValuesPreview, SymbolLinkageMarkers, or legacy test discovery is required to expand @Test")
 #endif
 
 /// A type describing the expansion of the `@Test` attribute macro.
diff --git a/Tests/TestingMacrosTests/TestDeclarationMacroTests.swift b/Tests/TestingMacrosTests/TestDeclarationMacroTests.swift
index aec6d2c10..226757733 100644
--- a/Tests/TestingMacrosTests/TestDeclarationMacroTests.swift
+++ b/Tests/TestingMacrosTests/TestDeclarationMacroTests.swift
@@ -472,7 +472,9 @@ struct TestDeclarationMacroTests {
   func differentFunctionTypes(input: String, expectedTypeName: String?, otherCode: String?) throws {
     let (output, _) = try parse(input)
 
-#if hasFeature(SymbolLinkageMarkers)
+#if compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)
+    #expect(output.contains("@section"))
+#elseif hasFeature(SymbolLinkageMarkers)
     #expect(output.contains("@_section"))
 #endif
 #if !SWT_NO_LEGACY_TEST_DISCOVERY
diff --git a/Tests/TestingTests/DiscoveryTests.swift b/Tests/TestingTests/DiscoveryTests.swift
index 24d2eecfa..42e5170f2 100644
--- a/Tests/TestingTests/DiscoveryTests.swift
+++ b/Tests/TestingTests/DiscoveryTests.swift
@@ -58,7 +58,7 @@ struct DiscoveryTests {
   }
 #endif
 
-#if !SWT_NO_DYNAMIC_LINKING && hasFeature(SymbolLinkageMarkers)
+#if !SWT_NO_DYNAMIC_LINKING && ((compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)) || hasFeature(SymbolLinkageMarkers))
   struct MyTestContent: DiscoverableAsTestContent {
     typealias TestContentAccessorHint = UInt32
 
@@ -80,6 +80,18 @@ struct DiscoveryTests {
       record.context
     }
 
+#if compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)
+#if objectFormat(MachO)
+    @section("__DATA_CONST,__swift5_tests")
+#elseif objectFormat(ELF) || objectFormat(Wasm)
+    @section("swift5_tests")
+#elseif objectFormat(COFF)
+    @section(".sw5test$B")
+#else
+    @__testing(warning: "Platform-specific implementation missing: object format unknown")
+#endif
+    @used
+#else
 #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS) || os(visionOS)
     @_section("__DATA_CONST,__swift5_tests")
 #elseif os(Linux) || os(FreeBSD) || os(OpenBSD) || os(Android) || os(WASI)
@@ -90,6 +102,7 @@ struct DiscoveryTests {
     @__testing(warning: "Platform-specific implementation missing: test content section name unavailable")
 #endif
     @_used
+#endif
     private static let record: __TestContentRecord = (
       0xABCD1234,
       0,
@@ -144,7 +157,7 @@ struct DiscoveryTests {
   }
 #endif
 
-#if !SWT_NO_LEGACY_TEST_DISCOVERY && hasFeature(SymbolLinkageMarkers)
+#if !SWT_NO_LEGACY_TEST_DISCOVERY && ((compiler(>=6.3) && hasFeature(CompileTimeValuesPreview)) || hasFeature(SymbolLinkageMarkers))
   @Test("Legacy test discovery finds the same number of tests") func discoveredTestCount() async {
     let oldFlag = Environment.variable(named: "SWT_USE_LEGACY_TEST_DISCOVERY")
     defer {