diff --git a/src/main/java/com/googlesource/gerrit/plugins/automerger/AutomergeChangeAction.java b/src/main/java/com/googlesource/gerrit/plugins/automerger/AutomergeChangeAction.java
index 0990ec5..d27638e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/automerger/AutomergeChangeAction.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/automerger/AutomergeChangeAction.java
@@ -71,7 +71,7 @@
 
     MultipleDownstreamMergeInput mdsMergeInput = new MultipleDownstreamMergeInput();
     mdsMergeInput.dsBranchMap = branchMap;
-    mdsMergeInput.sourceId = change.getKey().get();
+    mdsMergeInput.sourceId = change.getId().get();
     mdsMergeInput.project = change.getProject().get();
     mdsMergeInput.topic = change.getTopic();
     mdsMergeInput.subject = change.getSubject();
diff --git a/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java b/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
index a2ce9fe..fcfb82f 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/automerger/DownstreamCreator.java
@@ -424,7 +424,7 @@
 
     MultipleDownstreamMergeInput mdsMergeInput = new MultipleDownstreamMergeInput();
     mdsMergeInput.dsBranchMap = dsBranchMap;
-    mdsMergeInput.sourceId = change.id;
+    mdsMergeInput.sourceId = change._number;
     mdsMergeInput.project = change.project;
     mdsMergeInput.topic = change.topic;
     mdsMergeInput.subject = change.subject;
@@ -524,7 +524,7 @@
     gApi.changes().id(changeNumber).abandon(abandonInput);
   }
 
-  private String setTopic(String sourceId, String topic) throws RestApiException {
+  private String setTopic(int sourceId, String topic) throws RestApiException {
     if (topic == null || topic.isEmpty()) {
       topic = "am-" + UUID.randomUUID().toString();
       log.debug("Setting original change {} topic to {}", sourceId, topic);
diff --git a/src/main/java/com/googlesource/gerrit/plugins/automerger/MultipleDownstreamMergeInput.java b/src/main/java/com/googlesource/gerrit/plugins/automerger/MultipleDownstreamMergeInput.java
index 99903d1..f836307 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/automerger/MultipleDownstreamMergeInput.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/automerger/MultipleDownstreamMergeInput.java
@@ -21,7 +21,7 @@
  */
 public class MultipleDownstreamMergeInput {
   public Map<String, Boolean> dsBranchMap;
-  public String sourceId;
+  public int sourceId;
   public String project;
   public String topic;
   public String subject;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/automerger/SingleDownstreamMergeInput.java b/src/main/java/com/googlesource/gerrit/plugins/automerger/SingleDownstreamMergeInput.java
index 8f923b9..51fde18 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/automerger/SingleDownstreamMergeInput.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/automerger/SingleDownstreamMergeInput.java
@@ -17,7 +17,7 @@
 /** Class to hold input for a merge for a single source change and destination branch. */
 public class SingleDownstreamMergeInput {
   public String currentRevision;
-  public String sourceId;
+  public int sourceId;
   public String project;
   public String topic;
   public String subject;