diff --git a/changelog.html b/changelog.html
index 7e7da28791422359b59c7aaae50abbc92c6c05f7..951daff7768e2a843b3043197b1a3f4133e3b00a 100644
--- a/changelog.html
+++ b/changelog.html
@@ -55,6 +55,9 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
+  <li class='major bug'>
+    Build format change migrator in 1.597 did not work on some Windows systems.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-26519">issue 26519</a>)
   <li class=bug>
     Errors in some Maven builds since 1.598.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-26601">issue 26601</a>)
@@ -81,9 +84,6 @@ Upcoming changes</a>
 </div><!--=END=-->
 <h3><a name=v1.598>What's new in 1.598</a> (2015/01/25)</h3>
 <ul class=image>
-  <li class='major bug'>
-    Build format change migrator in 1.597 did not work on some Windows systems.
-    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-26519">issue 26519</a>)
   <li class=bug>
     FutureImpl does not cancel its start future.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-25514">issue 25514</a>)
diff --git a/core/src/main/java/jenkins/model/RunIdMigrator.java b/core/src/main/java/jenkins/model/RunIdMigrator.java
index a5be92c830118928f4d3518325dc3b36f2746d96..4666a5fb8655f146814ab6cf9ac284ba23646a34 100644
--- a/core/src/main/java/jenkins/model/RunIdMigrator.java
+++ b/core/src/main/java/jenkins/model/RunIdMigrator.java
@@ -200,32 +200,22 @@ public final class RunIdMigrator {
         while (it.hasNext()) {
             File kid = it.next();
             String name = kid.getName();
-            boolean numeric = false;
             try {
                 Integer.parseInt(name);
-                numeric = true;
-            } catch (NumberFormatException x) {}
+            } catch (NumberFormatException x) {
+                LOGGER.log(FINE, "ignoring nonnumeric entry {0}", name);
+                continue;
+            }
             try {
-                String link = Util.resolveSymlink(kid);
-                if (link == null && numeric && kid.isFile()) { // legacy Windows format
-                    link = FileUtils.readFileToString(kid);
-                } else if (link == null) {
-                    if (numeric) {
-                        if (kid.isDirectory()) {
-                            LOGGER.log(FINE, "skipping deletion of directory {0}", name);
-                        } else {
-                            LOGGER.log(WARNING, "need to delete non-symlink numeric directory entry {0}", name);
-                            Util.deleteFile(kid);
-                        }
-                    }
+                if (Util.isSymlink(kid)) {
+                    LOGGER.log(FINE, "deleting build number symlink {0} → {1}", new Object[] {name, Util.resolveSymlink(kid)});
+                } else if (kid.isDirectory()) {
+                    LOGGER.log(FINE, "ignoring build directory {0}", name);
                     continue;
-                }
-                if (numeric) {
-                    LOGGER.log(FINE, "deleting build number symlink {0} → {1}", new Object[] {name, link});
-                    Util.deleteFile(kid);
                 } else {
-                    LOGGER.log(FINE, "skipping other symlink {0} → {1}", new Object[] {name, link});
+                    LOGGER.log(WARNING, "need to delete anomalous file entry {0}", name);
                 }
+                Util.deleteFile(kid);
                 it.remove();
             } catch (Exception x) {
                 LOGGER.log(WARNING, "failed to process " + kid, x);
diff --git a/core/src/test/java/jenkins/model/RunIdMigratorTest.java b/core/src/test/java/jenkins/model/RunIdMigratorTest.java
index ce5c6d89e6110878f856c4bee662f87e23cf47f0..fb9805db779d2ea24e2f7e53b1040cf222875e35 100644
--- a/core/src/test/java/jenkins/model/RunIdMigratorTest.java
+++ b/core/src/test/java/jenkins/model/RunIdMigratorTest.java
@@ -42,7 +42,6 @@ import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.rules.TemporaryFolder;
-import org.jvnet.hudson.test.Issue;
 
 public class RunIdMigratorTest {
 
@@ -129,18 +128,6 @@ 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());
     }
 
-    @Issue("JENKINS-26519")
-    @Test public void windowsQuasiLinks() throws Exception {
-        write("2014-01-02_03-04-05/build.xml", "<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <number>99</number>\n  <otherstuff>ok</otherstuff>\n</run>");
-        write("99", "2014-01-02_03-04-05");
-        write("lastFailedBuild", "-1");
-        write("lastSuccessfulBuild", "99");
-        assertEquals("{2014-01-02_03-04-05={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <number>99</number>\n  <otherstuff>ok</otherstuff>\n</run>'}, 99='2014-01-02_03-04-05', lastFailedBuild='-1', lastSuccessfulBuild='99'}", summarize());
-        assertTrue(migrator.migrate(dir, null));
-        assertEquals("{99={build.xml='<?xml version='1.0' encoding='UTF-8'?>\n<run>\n  <stuff>ok</stuff>\n  <id>2014-01-02_03-04-05</id>\n  <timestamp>1388649845000</timestamp>\n  <otherstuff>ok</otherstuff>\n</run>'}, lastFailedBuild='-1', lastSuccessfulBuild='99', legacyIds='2014-01-02_03-04-05 99\n'}", summarize());
-        assertEquals(99, migrator.findNumber("2014-01-02_03-04-05"));
-    }
-
     // TODO test sane recovery from various error conditions
 
     private void write(String file, String text) throws Exception {