diff --git a/.gitignore b/.gitignore
index 9ae45758..6a8ca091 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,3 +9,4 @@ lib
 query.ser
 datanucleus.txt
 tck.txt
+*.claude
diff --git a/api/src/main/java/javax/jdo/LegacyJava.java b/api/src/main/java/javax/jdo/LegacyJava.java
index a708acbd..bec99cf2 100644
--- a/api/src/main/java/javax/jdo/LegacyJava.java
+++ b/api/src/main/java/javax/jdo/LegacyJava.java
@@ -109,7 +109,7 @@ public static class SecurityManager {
 
     public void checkPermission(JDOPermission permission) {
       try {
-        checkPermissionMethod.invoke(null, permission);
+        checkPermissionMethod.invoke(sm, permission);
       } catch (IllegalAccessException | InvocationTargetException e) {
         throw new JDOFatalInternalException(e.getMessage());
       }
@@ -134,8 +134,8 @@ public void updateSecurityManager(Object sm) {
    */
   private static boolean initIsSecurityDeprecated() {
     try {
-      Method getSecurityManager = System.class.getMethod("getSecurityManager");
-      return getSecurityManager.isAnnotationPresent(Deprecated.class);
+      System.class.getMethod("getSecurityManager");
+      return false;
     } catch (NoSuchMethodException e) {
       return true;
     }
diff --git a/api/src/test/java/javax/jdo/LegacyJavaTest.java b/api/src/test/java/javax/jdo/LegacyJavaTest.java
new file mode 100644
index 00000000..0c744bcc
--- /dev/null
+++ b/api/src/test/java/javax/jdo/LegacyJavaTest.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package javax.jdo;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.security.Permission;
+import javax.jdo.spi.JDOImplHelper;
+import javax.jdo.spi.JDOPermission;
+import org.junit.jupiter.api.Test;
+
+public class LegacyJavaTest {
+
+  @Test
+  public void testJDOImplHelper() {
+    // Try without security manager
+    assertNotNull(JDOImplHelper.getInstance());
+
+    if (LegacyJava.isSecurityManagerDeprecated()) {
+      return;
+    }
+    SecurityManager oldSecMgr = System.getSecurityManager();
+    try {
+      System.setSecurityManager(new MySecurityManager(JDOPermission.GET_METADATA));
+    } catch (UnsupportedOperationException e) {
+      // Running 24, SecurityManager is present but disabled by default.
+      return;
+    }
+
+    try {
+      // Try with security manager
+      assertThrows(JDOFatalInternalException.class, JDOImplHelper::getInstance);
+    } finally {
+      System.setSecurityManager(oldSecMgr);
+    }
+  }
+
+  public class MySecurityManager extends SecurityManager {
+    private final Permission invalidPermission;
+
+    public MySecurityManager(JDOPermission invalidPermission) {
+      this.invalidPermission = invalidPermission;
+    }
+
+    @Override
+    public void checkPermission(Permission perm) {
+      if (perm == invalidPermission)
+        throw new SecurityException("Permission not given: " + perm.getName());
+    }
+  }
+}
diff --git a/tck/src/main/java/org/apache/jdo/tck/api/persistencemanagerfactory/CloseWithoutPermissionThrowsSecurityException.java b/tck/src/main/java/org/apache/jdo/tck/api/persistencemanagerfactory/CloseWithoutPermissionThrowsSecurityException.java
index d88c1c0d..fb9c3bf4 100644
--- a/tck/src/main/java/org/apache/jdo/tck/api/persistencemanagerfactory/CloseWithoutPermissionThrowsSecurityException.java
+++ b/tck/src/main/java/org/apache/jdo/tck/api/persistencemanagerfactory/CloseWithoutPermissionThrowsSecurityException.java
@@ -59,8 +59,9 @@ private void closeWithMySecurityManager(PersistenceManagerFactory pmf) {
     SecurityManager oldSecMgr = System.getSecurityManager();
     try {
       System.setSecurityManager(new MySecurityManager());
-    } catch (SecurityException se) {
-      // running with the TCK SecurityManager; don't run this test
+    } catch (SecurityException | UnsupportedOperationException se) {
+      // SecurityException: running with the TCK SecurityManager; don't run this test
+      // UnsupportedOperationException: running Java 24, SecurityManager is present but disabled
       return;
     }