diff --git a/.github/workflows/ci-swiftpm.yml b/.github/workflows/ci-swiftpm.yml
index e15c91aa1..174f2fd50 100644
--- a/.github/workflows/ci-swiftpm.yml
+++ b/.github/workflows/ci-swiftpm.yml
@@ -50,3 +50,16 @@ jobs:
       - uses: actions/checkout@v4
       - run: swift build -Xswiftc -suppress-warnings
       - run: swift test -Xswiftc -suppress-warnings --enable-test-discovery
+
+  swiftpm_windows:
+    name: SwiftPM, Windows
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install Swift
+        uses: compnerd/gha-setup-swift@main
+        with:
+          branch: swift-5.9-release
+          tag: 5.9-RELEASE
+      - name: Test Windows
+        run: swift test -Xswiftc -suppress-warnings
diff --git a/Sources/Nimble/Matchers/PostNotification.swift b/Sources/Nimble/Matchers/PostNotification.swift
index 6f604ae8c..c848b968a 100644
--- a/Sources/Nimble/Matchers/PostNotification.swift
+++ b/Sources/Nimble/Matchers/PostNotification.swift
@@ -43,7 +43,11 @@ internal class NotificationCollector {
     }
 }
 
+#if !os(Windows)
 private let mainThread = pthread_self()
+#else
+private let mainThread = Thread.mainThread
+#endif
 
 private func _postNotifications<Out>(
     _ predicate: Predicate<[Notification]>,
diff --git a/Sources/Nimble/Utils/AsyncAwait.swift b/Sources/Nimble/Utils/AsyncAwait.swift
index 12547249f..a21dfd2cc 100644
--- a/Sources/Nimble/Utils/AsyncAwait.swift
+++ b/Sources/Nimble/Utils/AsyncAwait.swift
@@ -1,6 +1,9 @@
 #if !os(WASI)
 
+#if canImport(CoreFoundation)
 import CoreFoundation
+#endif
+
 import Dispatch
 import Foundation
 
diff --git a/Sources/Nimble/Utils/AsyncTimerSequence.swift b/Sources/Nimble/Utils/AsyncTimerSequence.swift
index 6bd46b83c..83c2485f9 100644
--- a/Sources/Nimble/Utils/AsyncTimerSequence.swift
+++ b/Sources/Nimble/Utils/AsyncTimerSequence.swift
@@ -1,6 +1,8 @@
 #if !os(WASI)
 
+#if canImport(CoreFoundation)
 import CoreFoundation
+#endif
 import Dispatch
 import Foundation
 
diff --git a/Sources/Nimble/Utils/PollAwait.swift b/Sources/Nimble/Utils/PollAwait.swift
index 177bd094b..161e9552a 100644
--- a/Sources/Nimble/Utils/PollAwait.swift
+++ b/Sources/Nimble/Utils/PollAwait.swift
@@ -1,6 +1,8 @@
 #if !os(WASI)
 
+#if canImport(CoreFoundation)
 import CoreFoundation
+#endif
 import Dispatch
 import Foundation
 
@@ -192,6 +194,7 @@ internal class AwaitPromiseBuilder<T> {
             let timedOutSem = DispatchSemaphore(value: 0)
             let semTimedOutOrBlocked = DispatchSemaphore(value: 0)
             semTimedOutOrBlocked.signal()
+            #if canImport(CoreFoundation)
             let runLoop = CFRunLoopGetMain()
             #if canImport(Darwin)
                 let runLoopMode = CFRunLoopMode.defaultMode.rawValue
@@ -209,12 +212,30 @@ internal class AwaitPromiseBuilder<T> {
             }
             // potentially interrupt blocking code on run loop to let timeout code run
             CFRunLoopStop(runLoop)
+            #else
+            let runLoop = RunLoop.main
+            runLoop.perform(inModes: [.default], block: {
+                if semTimedOutOrBlocked.wait(timeout: .now()) == .success {
+                    timedOutSem.signal()
+                    semTimedOutOrBlocked.signal()
+                    if self.promise.resolveResult(.timedOut) {
+                        RunLoop.main._stop()
+                    }
+                }
+            })
+            // potentially interrupt blocking code on run loop to let timeout code run
+            runLoop._stop()
+            #endif
             let now = DispatchTime.now() + forcefullyAbortTimeout.dispatchTimeInterval
             let didNotTimeOut = timedOutSem.wait(timeout: now) != .success
             let timeoutWasNotTriggered = semTimedOutOrBlocked.wait(timeout: .now()) == .success
             if didNotTimeOut && timeoutWasNotTriggered {
                 if self.promise.resolveResult(.blockedRunLoop) {
+                    #if canImport(CoreFoundation)
                     CFRunLoopStop(CFRunLoopGetMain())
+                    #else
+                    RunLoop.main._stop()
+                    #endif
                 }
             }
         }
@@ -302,7 +323,11 @@ internal class Awaiter {
                     if completionCount < 2 {
                         func completeBlock() {
                             if promise.resolveResult(.completed(result)) {
+                                #if canImport(CoreFoundation)
                                 CFRunLoopStop(CFRunLoopGetMain())
+                                #else
+                                RunLoop.main._stop()
+                                #endif
                             }
                         }
 
@@ -340,12 +365,20 @@ internal class Awaiter {
                 do {
                     if let result = try closure() {
                         if promise.resolveResult(.completed(result)) {
+                            #if canImport(CoreFoundation)
                             CFRunLoopStop(CFRunLoopGetCurrent())
+                            #else
+                            RunLoop.current._stop()
+                            #endif
                         }
                     }
                 } catch let error {
                     if promise.resolveResult(.errorThrown(error)) {
+                        #if canImport(CoreFoundation)
                         CFRunLoopStop(CFRunLoopGetCurrent())
+                        #else
+                        RunLoop.current._stop()
+                        #endif
                     }
                 }
             }
diff --git a/Tests/NimbleTests/AsyncAwaitTest.swift b/Tests/NimbleTests/AsyncAwaitTest.swift
index 3c13dea76..ff80b8df0 100644
--- a/Tests/NimbleTests/AsyncAwaitTest.swift
+++ b/Tests/NimbleTests/AsyncAwaitTest.swift
@@ -85,7 +85,7 @@ final class AsyncAwaitTest: XCTestCase { // swiftlint:disable:this type_body_len
     @MainActor
     func testToEventuallyOnMain() async {
         await expect(1).toEventually(equal(1), timeout: .seconds(300))
-        await expect { usleep(10); return 1 }.toEventually(equal(1))
+        await expect { try? await Task.sleep(nanoseconds: 10_000); return 1 }.toEventually(equal(1))
     }
 
     @MainActor
diff --git a/Tests/NimbleTests/Matchers/ThrowAssertionTest.swift b/Tests/NimbleTests/Matchers/ThrowAssertionTest.swift
index 916104e80..8d547d128 100644
--- a/Tests/NimbleTests/Matchers/ThrowAssertionTest.swift
+++ b/Tests/NimbleTests/Matchers/ThrowAssertionTest.swift
@@ -9,19 +9,19 @@ private let error: Error = NSError(domain: "test", code: 0, userInfo: nil)
 
 final class ThrowAssertionTest: XCTestCase {
     func testPositiveMatch() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         expect { () -> Void in fatalError() }.to(throwAssertion())
         #endif
     }
 
     func testErrorThrown() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         expect { throw error }.toNot(throwAssertion())
         #endif
     }
 
     func testPostAssertionCodeNotRun() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         var reachedPoint1 = false
         var reachedPoint2 = false
 
@@ -37,7 +37,7 @@ final class ThrowAssertionTest: XCTestCase {
     }
 
     func testNegativeMatch() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         var reachedPoint1 = false
 
         expect { reachedPoint1 = true }.toNot(throwAssertion())
@@ -47,7 +47,7 @@ final class ThrowAssertionTest: XCTestCase {
     }
 
     func testPositiveMessage() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         failsWithErrorMessage("expected to throw an assertion") {
             expect { () -> Void? in return }.to(throwAssertion())
         }
@@ -59,7 +59,7 @@ final class ThrowAssertionTest: XCTestCase {
     }
 
     func testNegativeMessage() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         failsWithErrorMessage("expected to not throw an assertion") {
             expect { () -> Void in fatalError() }.toNot(throwAssertion())
         }
@@ -67,13 +67,13 @@ final class ThrowAssertionTest: XCTestCase {
     }
 
     func testNonVoidClosure() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         expect { () -> Int in fatalError() }.to(throwAssertion())
         #endif
     }
 
     func testChainOnThrowAssertion() {
-        #if arch(x86_64) || arch(arm64)
+        #if (arch(x86_64) || arch(arm64)) && !os(Windows)
         expect { () -> Int in return 5 }.toNot(throwAssertion()).to(equal(5))
         #endif
     }
diff --git a/Tests/NimbleTests/PollingTest.swift b/Tests/NimbleTests/PollingTest.swift
index 2abe01402..0b7a7c394 100644
--- a/Tests/NimbleTests/PollingTest.swift
+++ b/Tests/NimbleTests/PollingTest.swift
@@ -1,7 +1,9 @@
 #if !os(WASI)
 
 import Dispatch
+#if canImport(CoreFoundation)
 import CoreFoundation
+#endif
 import Foundation
 import XCTest
 import Nimble