diff --git a/src/main/java/io/reactivex/Maybe.java b/src/main/java/io/reactivex/Maybe.java
index fbb5bd0dca..9804233003 100644
--- a/src/main/java/io/reactivex/Maybe.java
+++ b/src/main/java/io/reactivex/Maybe.java
@@ -2606,7 +2606,7 @@ public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<?
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        return new MaybeFlatMapIterableFlowable<T, U>(this, mapper);
+        return RxJavaPlugins.onAssembly(new MaybeFlatMapIterableFlowable<T, U>(this, mapper));
     }
 
     /**
@@ -2628,7 +2628,7 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
      */
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        return new MaybeFlatMapIterableObservable<T, U>(this, mapper);
+        return RxJavaPlugins.onAssembly(new MaybeFlatMapIterableObservable<T, U>(this, mapper));
     }
 
     /**
diff --git a/src/main/java/io/reactivex/Observable.java b/src/main/java/io/reactivex/Observable.java
index 4b42c374a0..592bffc6c4 100644
--- a/src/main/java/io/reactivex/Observable.java
+++ b/src/main/java/io/reactivex/Observable.java
@@ -6347,7 +6347,7 @@ public final <K> Observable<T> distinct(Function<? super T, K> keySelector) {
     public final <K> Observable<T> distinct(Function<? super T, K> keySelector, Callable<? extends Collection<? super K>> collectionSupplier) {
         ObjectHelper.requireNonNull(keySelector, "keySelector is null");
         ObjectHelper.requireNonNull(collectionSupplier, "collectionSupplier is null");
-        return new ObservableDistinct<T, K>(this, keySelector, collectionSupplier);
+        return RxJavaPlugins.onAssembly(new ObservableDistinct<T, K>(this, keySelector, collectionSupplier));
     }
 
     /**
@@ -8387,7 +8387,7 @@ public final ConnectableObservable<T> publish() {
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <R> Observable<R> publish(Function<? super Observable<T>, ? extends ObservableSource<R>> selector) {
         ObjectHelper.requireNonNull(selector, "selector is null");
-        return new ObservablePublishSelector<T, R>(this, selector);
+        return RxJavaPlugins.onAssembly(new ObservablePublishSelector<T, R>(this, selector));
     }
 
     /**
diff --git a/src/main/java/io/reactivex/Single.java b/src/main/java/io/reactivex/Single.java
index e54dddaf1e..0d41a7d8f4 100644
--- a/src/main/java/io/reactivex/Single.java
+++ b/src/main/java/io/reactivex/Single.java
@@ -1958,7 +1958,7 @@ public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publ
     @BackpressureSupport(BackpressureKind.FULL)
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        return new SingleFlatMapIterableFlowable<T, U>(this, mapper);
+        return RxJavaPlugins.onAssembly(new SingleFlatMapIterableFlowable<T, U>(this, mapper));
     }
 
     /**
@@ -1980,7 +1980,7 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
      */
     @SchedulerSupport(SchedulerSupport.NONE)
     public final <U> Observable<U> flattenAsObservable(final Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        return new SingleFlatMapIterableObservable<T, U>(this, mapper);
+        return RxJavaPlugins.onAssembly(new SingleFlatMapIterableObservable<T, U>(this, mapper));
     }
 
     /**