diff --git a/Sources/Testing/Running/XCTestScaffold.swift b/Sources/Testing/Running/XCTestScaffold.swift
index 972581ec..dd6362a8 100644
--- a/Sources/Testing/Running/XCTestScaffold.swift
+++ b/Sources/Testing/Running/XCTestScaffold.swift
@@ -8,7 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
-#if !SWT_NO_XCTEST_SCAFFOLDING
+#if !SWT_NO_XCTEST_SCAFFOLDING && canImport(XCTest)
 private import TestingInternals
 public import XCTest
 
@@ -25,19 +25,6 @@ extension XCTSourceCodeContext {
     self.init(callStackAddresses: addresses, location: sourceLocation)
   }
 }
-
-/// An error that is reported by ``XCTestScaffold`` when a test times out.
-///
-/// This type is not part of the public interface of the testing library.
-struct TimeoutError: Error, CustomStringConvertible {
-  /// The time limit exceeded by the test that timed out.
-  var timeLimit: TimeValue
-
-  var description: String {
-    "Timed out after \(timeLimit) seconds."
-  }
-}
-
 extension XCTIssue {
   init(_ issue: Issue, processLaunchedByXcode: Bool) {
     var error = issue.error
diff --git a/Sources/Testing/Traits/TimeLimitTrait.swift b/Sources/Testing/Traits/TimeLimitTrait.swift
index a70c14a3..153a19bd 100644
--- a/Sources/Testing/Traits/TimeLimitTrait.swift
+++ b/Sources/Testing/Traits/TimeLimitTrait.swift
@@ -108,6 +108,18 @@ extension Test {
 
 // MARK: -
 
+/// An error that is reported by ``XCTestScaffold`` when a test times out.
+///
+/// This type is not part of the public interface of the testing library.
+struct TimeoutError: Error, CustomStringConvertible {
+  /// The time limit exceeded by the test that timed out.
+  var timeLimit: TimeValue
+
+  var description: String {
+    "Timed out after \(timeLimit) seconds."
+  }
+}
+
 #if !SWT_NO_UNSTRUCTURED_TASKS
 /// Invoke a function with a timeout.
 ///
diff --git a/Tests/TestingMacrosTests/TestSupport/Scaffolding.swift b/Tests/TestingMacrosTests/TestSupport/Scaffolding.swift
index 813b442a..766a7d61 100644
--- a/Tests/TestingMacrosTests/TestSupport/Scaffolding.swift
+++ b/Tests/TestingMacrosTests/TestSupport/Scaffolding.swift
@@ -8,7 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
-#if !SWT_NO_XCTEST_SCAFFOLDING && !SWIFT_PM_SUPPORTS_SWIFT_TESTING
+#if !SWT_NO_XCTEST_SCAFFOLDING && !SWIFT_PM_SUPPORTS_SWIFT_TESTING && canImport(XCTest)
 import XCTest
 import Testing
 
diff --git a/Tests/TestingTests/IssueTests.swift b/Tests/TestingTests/IssueTests.swift
index a17f5c1f..b0135d85 100644
--- a/Tests/TestingTests/IssueTests.swift
+++ b/Tests/TestingTests/IssueTests.swift
@@ -10,6 +10,7 @@
 
 @testable @_spi(Experimental) @_spi(ForToolsIntegrationOnly) import Testing
 private import TestingInternals
+import Foundation
 
 #if canImport(XCTest)
 import XCTest
diff --git a/Tests/TestingTests/ObjCInteropTests.swift b/Tests/TestingTests/ObjCInteropTests.swift
index eacc601c..179460af 100644
--- a/Tests/TestingTests/ObjCInteropTests.swift
+++ b/Tests/TestingTests/ObjCInteropTests.swift
@@ -8,6 +8,7 @@
  See https://swift.org/CONTRIBUTORS.txt for Swift project authors
  */
 
+#if canImport(XCTest)
 import XCTest
 @testable @_spi(ForToolsIntegrationOnly) import Testing
 
@@ -106,3 +107,4 @@ struct ObjCAndXCTestInteropTests {
     }
   }
 }
+#endif
diff --git a/Tests/TestingTests/RunnerTests.swift b/Tests/TestingTests/RunnerTests.swift
index 28c81122..9b860b67 100644
--- a/Tests/TestingTests/RunnerTests.swift
+++ b/Tests/TestingTests/RunnerTests.swift
@@ -10,6 +10,7 @@
 
 #if canImport(XCTest)
 import XCTest
+#endif
 @testable @_spi(Experimental) @_spi(ForToolsIntegrationOnly) import Testing
 
 struct MyError: Error, Equatable {
@@ -35,6 +36,7 @@ private let randomNumber = Int.random(in: 0 ..< .max)
   throw MyParameterizedError(index: i)
 }
 
+#if canImport(XCTest)
 @Suite(.hidden, .disabled())
 struct NeverRunTests {
   private static var someCondition: Bool {
diff --git a/Tests/TestingTests/TestSupport/Scaffolding.swift b/Tests/TestingTests/TestSupport/Scaffolding.swift
index 813b442a..766a7d61 100644
--- a/Tests/TestingTests/TestSupport/Scaffolding.swift
+++ b/Tests/TestingTests/TestSupport/Scaffolding.swift
@@ -8,7 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
-#if !SWT_NO_XCTEST_SCAFFOLDING && !SWIFT_PM_SUPPORTS_SWIFT_TESTING
+#if !SWT_NO_XCTEST_SCAFFOLDING && !SWIFT_PM_SUPPORTS_SWIFT_TESTING && canImport(XCTest)
 import XCTest
 import Testing