diff --git a/Documentation/cmd-stream-events.txt b/Documentation/cmd-stream-events.txt
index e8c5213e8f..f0ad460380 100644
--- a/Documentation/cmd-stream-events.txt
+++ b/Documentation/cmd-stream-events.txt
@@ -234,6 +234,8 @@ patchSet:: link:json.html#patchSet[patchSet attribute]
 
 reviewer:: link:json.html#account[account attribute]
 
+adder:: user that added the reviewer as link:json.html#account[account attribute]
+
 eventCreatedOn:: Time in seconds since the UNIX epoch when this event was
 created.
 
diff --git a/java/com/google/gerrit/server/events/ReviewerAddedEvent.java b/java/com/google/gerrit/server/events/ReviewerAddedEvent.java
index 9644456d4f..ea6bda3e74 100644
--- a/java/com/google/gerrit/server/events/ReviewerAddedEvent.java
+++ b/java/com/google/gerrit/server/events/ReviewerAddedEvent.java
@@ -21,6 +21,7 @@ import com.google.gerrit.server.data.AccountAttribute;
 public class ReviewerAddedEvent extends PatchSetEvent {
   static final String TYPE = "reviewer-added";
   public Supplier<AccountAttribute> reviewer;
+  public Supplier<AccountAttribute> adder;
 
   public ReviewerAddedEvent(Change change) {
     super(TYPE, change);
diff --git a/java/com/google/gerrit/server/events/StreamEventsApiListener.java b/java/com/google/gerrit/server/events/StreamEventsApiListener.java
index 3add4cac13..5b2c368ae8 100644
--- a/java/com/google/gerrit/server/events/StreamEventsApiListener.java
+++ b/java/com/google/gerrit/server/events/StreamEventsApiListener.java
@@ -317,6 +317,7 @@ public class StreamEventsApiListener
 
       event.change = changeAttributeSupplier(change, notes);
       event.patchSet = patchSetAttributeSupplier(change, psUtil.current(notes));
+      event.adder = accountAttributeSupplier(ev.getWho());
       for (AccountInfo reviewer : ev.getReviewers()) {
         event.reviewer = accountAttributeSupplier(reviewer);
         dispatcher.run(d -> d.postEvent(event));