diff --git a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java
index 14cf61ef970b..a9fb510ca397 100644
--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java
+++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/janitor/CatalogJanitor.java
@@ -164,14 +164,14 @@ private static boolean isRIT(AssignmentManager am) {
    */
   public int scan() throws IOException {
     int gcs = 0;
-    try {
-      if (!alreadyRunning.compareAndSet(false, true)) {
-        if (LOG.isDebugEnabled()) {
-          LOG.debug("CatalogJanitor already running");
-        }
-        // -1 indicates previous scan is in progress
-        return -1;
+    if (!alreadyRunning.compareAndSet(false, true)) {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("CatalogJanitor already running");
       }
+      // -1 indicates previous scan is in progress
+      return -1;
+    }
+    try {
       this.lastReport = scanForReport();
       if (!this.lastReport.isEmpty()) {
         LOG.warn(this.lastReport.toString());
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitor.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitor.java
index 259ff1636bf9..8ef72bbb6157 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitor.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/master/janitor/TestCatalogJanitor.java
@@ -20,6 +20,7 @@
 import static org.apache.hadoop.hbase.util.HFileArchiveTestingUtil.assertArchiveEqualToOriginal;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.doAnswer;
@@ -29,12 +30,15 @@
 import static org.mockito.Mockito.when;
 
 import java.io.IOException;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.SortedMap;
 import java.util.TreeMap;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.FileStatus;
@@ -690,6 +694,63 @@ public void testAlreadyRunningStatus() throws Exception {
     assertTrue(gcValues.contains(-1), "One janitor.scan() call should have returned -1");
   }
 
+  @Test
+  public void testAlreadyRunningStatusDoesNotClearLock() throws Exception {
+    CatalogJanitor spy = spy(this.janitor);
+
+    CountDownLatch scanStarted = new CountDownLatch(1);
+    CountDownLatch allowScanToFinish = new CountDownLatch(1);
+
+    doAnswer(invocation -> {
+      scanStarted.countDown();
+      allowScanToFinish.await();
+      return new CatalogJanitorReport();
+    }).when(spy).scanForReport();
+
+    Thread scanThread = new Thread(() -> {
+      try {
+        spy.scan();
+      } catch (IOException e) {
+        throw new RuntimeException(e);
+      }
+    });
+
+    // First scan acquires the lock and remains running.
+    scanThread.start();
+    assertTrue(scanStarted.await(5, TimeUnit.SECONDS));
+    LOG.info("First catalog janitor scan started and waiting to finish.");
+
+    // Second scan detects that another scan is running.
+    assertEquals(-1, spy.scan());
+    LOG.info("Second catalog janitor scan attempt returned -1.");
+
+    // The second scan must not clear the lock.
+    // Therefore, the third scan must also report that a scan is running.
+    try {
+      assertTimeoutPreemptively(
+        Duration.ofMinutes(1),
+        () -> {
+          int result = spy.scan();
+          LOG.info("Third catalog janitor scan attempt returned {}.", result);
+          assertEquals(-1, result);
+        }
+      );
+    } catch (AssertionError e) {
+      LOG.error(
+        "Third catalog janitor scan did not return -1 within 60 seconds; "
+          + "the scan may be running instead of returning -1.",
+        e
+      );
+      throw e;
+    } finally {
+      // Let the first scan finish.
+      LOG.info("Releasing first catalog janitor scan and waiting for it to complete.");
+      allowScanToFinish.countDown();
+      scanThread.join(5000);
+      assertFalse(scanThread.isAlive());
+    }
+  }
+
   private FileStatus[] addMockStoreFiles(int count, MasterServices services, Path storedir)
     throws IOException {
     // get the existing store files