diff --git a/src/main/scala/com/raquo/airstream/signal/Signal.scala b/src/main/scala/com/raquo/airstream/signal/Signal.scala
index 9cd7ac1f..00c142ef 100644
--- a/src/main/scala/com/raquo/airstream/signal/Signal.scala
+++ b/src/main/scala/com/raquo/airstream/signal/Signal.scala
@@ -137,6 +137,11 @@ trait Signal[+A] extends Observable[A] {
     super.onStart()
   }
 
+  override protected[this] def onStop(): Unit = {
+    super.onStop()
+    maybeLastSeenCurrentValue = js.undefined
+  }
+
   // @TODO[API] Use pattern match instead when isInstanceOf performance is fixed: https://github.com/scala-js/scala-js/issues/2066
   override protected def onAddedExternalObserver(observer: Observer[A]): Unit = {
     super.onAddedExternalObserver(observer)