diff --git a/core/src/main/java/jenkins/model/RunIdMigrator.java b/core/src/main/java/jenkins/model/RunIdMigrator.java
index 4666a5fb8655f146814ab6cf9ac284ba23646a34..88dc17b90026101b0a75a3abdca21bd1b8bab760 100644
--- a/core/src/main/java/jenkins/model/RunIdMigrator.java
+++ b/core/src/main/java/jenkins/model/RunIdMigrator.java
@@ -350,6 +350,12 @@ public final class RunIdMigrator {
             return;
         }
         for (File job : jobDirs) {
+
+            if (job.getName().equals("builds")) {
+                // Might be maven modules, matrix builds, etc. which are direct children of job
+                unmigrateBuildsDir(job);
+            }
+
             File[] kids = job.listFiles();
             if (kids == null) {
                 continue;
@@ -361,7 +367,8 @@ public final class RunIdMigrator {
                 if (kid.getName().equals("builds")) {
                     unmigrateBuildsDir(kid);
                 } else {
-                    // Might be jobs, modules, promotions, etc.; we assume an ItemGroup.getRootDirFor implementation returns grandchildren.
+                    // Might be jobs, modules, promotions, etc.; we assume an ItemGroup.getRootDirFor implementation
+                    // returns grandchildren, unmigrateJobsDir(job) call above handles children.
                     unmigrateJobsDir(kid);
                 }
             }
diff --git a/core/src/test/java/jenkins/model/RunIdMigratorTest.java b/core/src/test/java/jenkins/model/RunIdMigratorTest.java
index fb9805db779d2ea24e2f7e53b1040cf222875e35..4b890ac50a6d5b8de3d23dbf5678eeb7f3e19037 100644
--- a/core/src/test/java/jenkins/model/RunIdMigratorTest.java
+++ b/core/src/test/java/jenkins/model/RunIdMigratorTest.java
@@ -128,6 +128,26 @@ public class RunIdMigratorTest {
         assertEquals("{1=→2014-01-02_03-04-05, 2014-01-02_03-04-05={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <number>1</number>\n  <otherstuff>ok</otherstuff>\n</run>'}}", summarize());
     }
 
+    @Test public void reverseMatrixAfterNewBuilds() throws Exception {
+        File root = dir;
+        dir = new File(dir, "jobs/someproject/Environment=prod/builds");
+        write("1/build.xml", "<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <timestamp>1388649845000</timestamp>\n  <otherstuff>ok</otherstuff>\n</run>");
+        write("legacyIds", "");
+        assertEquals("{1={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <timestamp>1388649845000</timestamp>\n  <otherstuff>ok</otherstuff>\n</run>'}, legacyIds=''}", summarize());
+        RunIdMigrator.main(root.getAbsolutePath());
+        assertEquals("{1=→2014-01-02_03-04-05, 2014-01-02_03-04-05={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <number>1</number>\n  <otherstuff>ok</otherstuff>\n</run>'}}", summarize());
+    }
+
+    @Test public void reverseMavenAfterNewBuilds() throws Exception {
+        File root = dir;
+        dir = new File(dir, "jobs/someproject/test$test/builds");
+        write("1/build.xml", "<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <timestamp>1388649845000</timestamp>\n  <otherstuff>ok</otherstuff>\n</run>");
+        write("legacyIds", "");
+        assertEquals("{1={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <timestamp>1388649845000</timestamp>\n  <otherstuff>ok</otherstuff>\n</run>'}, legacyIds=''}", summarize());
+        RunIdMigrator.main(root.getAbsolutePath());
+        assertEquals("{1=→2014-01-02_03-04-05, 2014-01-02_03-04-05={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <number>1</number>\n  <otherstuff>ok</otherstuff>\n</run>'}}", summarize());
+    }
+
     // TODO test sane recovery from various error conditions
 
     private void write(String file, String text) throws Exception {