diff --git a/munit/js/src/main/scala/munit/internal/PlatformCompat.scala b/munit/js/src/main/scala/munit/internal/PlatformCompat.scala
index b5ed7e24..7a1ac67b 100644
--- a/munit/js/src/main/scala/munit/internal/PlatformCompat.scala
+++ b/munit/js/src/main/scala/munit/internal/PlatformCompat.scala
@@ -36,16 +36,20 @@ object PlatformCompat {
       ec: ExecutionContext
   ): Future[T] = {
     val onComplete = Promise[T]()
-    val timeoutHandle = timers.setTimeout(duration.toMillis) {
-      onComplete.tryFailure(
-        new TimeoutException(s"test timed out after $duration")
-      )
-    }
+    val timeoutHandle =
+      if (duration.isFinite)
+        Some(timers.setTimeout(duration.toMillis) {
+          onComplete.tryFailure(
+            new TimeoutException(s"test timed out after $duration")
+          )
+        })
+      else
+        None
     ec.execute(new Runnable {
       def run(): Unit = {
         startFuture().onComplete { result =>
           onComplete.tryComplete(result)
-          timers.clearTimeout(timeoutHandle)
+          timeoutHandle.foreach(timers.clearTimeout(_))
         }(ec)
       }
     })
diff --git a/munit/jvm/src/main/scala/munit/internal/PlatformCompat.scala b/munit/jvm/src/main/scala/munit/internal/PlatformCompat.scala
index ae6b19dc..c21126ef 100644
--- a/munit/jvm/src/main/scala/munit/internal/PlatformCompat.scala
+++ b/munit/jvm/src/main/scala/munit/internal/PlatformCompat.scala
@@ -56,19 +56,25 @@ object PlatformCompat {
       ec: ExecutionContext
   ): Future[T] = {
     val onComplete = Promise[T]()
-    val timeout = sh.schedule[Unit](
-      () =>
-        onComplete.tryFailure(
-          new TimeoutException(s"test timed out after $duration")
-        ),
-      duration.toMillis,
-      TimeUnit.MILLISECONDS
-    )
+    val timeout =
+      if (duration.isFinite)
+        Some(
+          sh.schedule[Unit](
+            () =>
+              onComplete.tryFailure(
+                new TimeoutException(s"test timed out after $duration")
+              ),
+            duration.toMillis,
+            TimeUnit.MILLISECONDS
+          )
+        )
+      else
+        None
     ec.execute(new Runnable {
       def run(): Unit = {
         startFuture().onComplete { result =>
           onComplete.tryComplete(result)
-          timeout.cancel(false)
+          timeout.foreach(_.cancel(false))
         }(ec)
       }
     })