diff --git a/src/main/java/io/reactivex/rxjava3/core/Observable.java b/src/main/java/io/reactivex/rxjava3/core/Observable.java
index fcf809cdf6..459d24a141 100644
--- a/src/main/java/io/reactivex/rxjava3/core/Observable.java
+++ b/src/main/java/io/reactivex/rxjava3/core/Observable.java
@@ -14147,7 +14147,7 @@ public final Observable<T> takeLast(long time, @NonNull TimeUnit unit, @NonNull
      * <img width="640" height="305" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/takeUntil.p.v3.png" alt="">
      * <p>
      * The difference between this operator and {@link #takeWhile(Predicate)} is that here, the condition is
-     * evaluated <em>after</em> the item is emitted.
+     * evaluated <em>after</em> the item is emitted. (Also, the condition is inverted.)
      *
      * <dl>
      *  <dt><b>Scheduler:</b></dt>