diff --git a/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManagerImpl.java b/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManagerImpl.java
index d1870ff49c34..40579c58f724 100644
--- a/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManagerImpl.java
+++ b/hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/server/upgrade/FinalizationManagerImpl.java
@@ -87,6 +87,9 @@ public UpgradeFinalization.StatusAndMessages finalizeUpgrade(
       throws IOException {
     Objects.requireNonNull(context, "Cannot finalize upgrade without " +
         "first building the upgrade context.");
+    if (context.getSCMContext().isInSafeMode()) {
+      throw new IOException("Finalization is not possible while SCM is in safemode");
+    }
     return upgradeFinalizer.finalize(upgradeClientID, context);
   }
 
diff --git a/hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/upgrade/TestFinalizationManagerImpl.java b/hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/upgrade/TestFinalizationManagerImpl.java
new file mode 100644
index 000000000000..7e695e8dbd8a
--- /dev/null
+++ b/hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/upgrade/TestFinalizationManagerImpl.java
@@ -0,0 +1,110 @@
+/*
+ * 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
+ *
+ *      http://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 org.apache.hadoop.hdds.scm.upgrade;
+
+import static org.apache.hadoop.hdds.upgrade.HDDSLayoutFeature.INITIAL_VERSION;
+import static org.apache.hadoop.hdds.upgrade.HDDSLayoutVersionManager.maxLayoutVersion;
+import static org.apache.hadoop.ozone.upgrade.UpgradeFinalization.Status.ALREADY_FINALIZED;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.mock;
+
+import java.io.IOException;
+import org.apache.hadoop.hdds.scm.ha.SCMContext;
+import org.apache.hadoop.hdds.scm.node.NodeManager;
+import org.apache.hadoop.hdds.scm.safemode.SCMSafeModeManager.SafeModeStatus;
+import org.apache.hadoop.hdds.scm.server.SCMStorageConfig;
+import org.apache.hadoop.hdds.scm.server.StorageContainerManager;
+import org.apache.hadoop.hdds.scm.server.upgrade.FinalizationManager;
+import org.apache.hadoop.hdds.scm.server.upgrade.FinalizationStateManager;
+import org.apache.hadoop.hdds.upgrade.HDDSLayoutVersionManager;
+import org.apache.hadoop.ozone.upgrade.UpgradeFinalization.StatusAndMessages;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Unit tests for {@link org.apache.hadoop.hdds.scm.server.upgrade.FinalizationManagerImpl}.
+ */
+public class TestFinalizationManagerImpl {
+
+  private static final String CLIENT_ID = "test-client";
+
+  /**
+   * Finalization must be rejected while SCM is in safe mode and finalization is needed.
+   */
+  @Test
+  public void testFinalizeThrowsWhenInSafeMode() throws Exception {
+    // Use INITIAL_VERSION so the cluster genuinely needs finalization.
+    FinalizationManager manager = buildManager(new HDDSLayoutVersionManager(INITIAL_VERSION.layoutVersion()));
+
+    SCMContext inSafeMode = createScmContext(SafeModeStatus.INITIAL);
+    manager.buildUpgradeContext(mock(NodeManager.class), inSafeMode);
+
+    IOException ex = assertThrows(IOException.class, () -> manager.finalizeUpgrade(CLIENT_ID));
+    assertThat(ex.getMessage()).containsIgnoringCase("safemode");
+  }
+
+  /**
+   * Finalization must be rejected while SCM is in safe mode even if finalization is not needed.
+   */
+  @Test
+  public void testAlreadyFinalizedClusterStillBlockedBySafeMode() throws Exception {
+    FinalizationManager manager = buildManager(new HDDSLayoutVersionManager(maxLayoutVersion()));
+
+    SCMContext inSafeMode = createScmContext(SafeModeStatus.INITIAL);
+    manager.buildUpgradeContext(mock(NodeManager.class), inSafeMode);
+
+    IOException ex = assertThrows(IOException.class, () -> manager.finalizeUpgrade(CLIENT_ID));
+    assertThat(ex.getMessage()).containsIgnoringCase("safemode");
+  }
+
+  /**
+   * Finalization must not be blocked when SCM is out of safe mode.
+   * Using maxLayoutVersion so the cluster is already finalized, which lets
+   * the call succeed without wiring up the full replication stack.
+   */
+  @Test
+  public void testFinalizeSucceedsWhenOutOfSafeMode() throws Exception {
+    FinalizationManager manager = buildManager(new HDDSLayoutVersionManager(maxLayoutVersion()));
+
+    SCMContext outOfSafeMode = createScmContext(SafeModeStatus.OUT_OF_SAFE_MODE);
+    manager.buildUpgradeContext(mock(NodeManager.class), outOfSafeMode);
+
+    StatusAndMessages result = manager.finalizeUpgrade(CLIENT_ID);
+    assertEquals(ALREADY_FINALIZED, result.status());
+  }
+
+  private static FinalizationManager buildManager(HDDSLayoutVersionManager lvm)
+      throws IOException {
+    // Use a local variable rather than chaining: the parent builder methods
+    // (setLayoutVersionManager, setStorage) return FinalizationManagerImpl.Builder,
+    // losing the subtype, so setFinalizationStateManager would not be visible.
+    FinalizationManagerTestImpl.Builder builder = new FinalizationManagerTestImpl.Builder();
+    builder.setLayoutVersionManager(lvm);
+    builder.setStorage(mock(SCMStorageConfig.class));
+    builder.setFinalizationStateManager(mock(FinalizationStateManager.class));
+    return builder.build();
+  }
+
+  private SCMContext createScmContext(SafeModeStatus safeMode) {
+    return new SCMContext.Builder()
+        .setSafeModeStatus(safeMode)
+        .setSCM(mock(StorageContainerManager.class))
+        .build();
+  }
+}