diff --git a/java/com/google/gerrit/server/git/SubmoduleOp.java b/java/com/google/gerrit/server/git/SubmoduleOp.java
index 56ed432a23..0e3e146273 100644
--- a/java/com/google/gerrit/server/git/SubmoduleOp.java
+++ b/java/com/google/gerrit/server/git/SubmoduleOp.java
@@ -14,6 +14,8 @@
 
 package com.google.gerrit.server.git;
 
+import static java.util.Comparator.comparing;
+
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.MultimapBuilder;
 import com.google.common.collect.SetMultimap;
@@ -47,6 +49,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -416,7 +419,10 @@ public class SubmoduleOp {
     DirCache dc = readTree(or.rw, currentCommit);
     DirCacheEditor ed = dc.editor();
     int count = 0;
-    for (SubmoduleSubscription s : targets.get(subscriber)) {
+
+    List<SubmoduleSubscription> subscriptions = new ArrayList<>(targets.get(subscriber));
+    Collections.sort(subscriptions, comparing((SubmoduleSubscription s) -> s.getPath()));
+    for (SubmoduleSubscription s : subscriptions) {
       if (count > 0) {
         msgbuf.append("\n\n");
       }
diff --git a/javatests/com/google/gerrit/acceptance/git/SubmoduleSubscriptionsWholeTopicMergeIT.java b/javatests/com/google/gerrit/acceptance/git/SubmoduleSubscriptionsWholeTopicMergeIT.java
index 7583830587..2812c8637e 100644
--- a/javatests/com/google/gerrit/acceptance/git/SubmoduleSubscriptionsWholeTopicMergeIT.java
+++ b/javatests/com/google/gerrit/acceptance/git/SubmoduleSubscriptionsWholeTopicMergeIT.java
@@ -346,17 +346,17 @@ public class SubmoduleSubscriptionsWholeTopicMergeIT extends AbstractSubmoduleSu
           "master",
           "Update git submodules\n\n"
               + "* Update "
-              + name("sub3")
+              + name("sub1")
               + " from branch 'master'\n  to "
-              + sub3HEAD
+              + sub1HEAD
               + "\n\n* Update "
               + name("sub2")
               + " from branch 'master'\n  to "
               + sub2HEAD
               + "\n\n* Update "
-              + name("sub1")
+              + name("sub3")
               + " from branch 'master'\n  to "
-              + sub1HEAD);
+              + sub3HEAD);
     }
 
     superRepo