diff --git a/src/org/openstreetmap/josm/data/osm/ChangesetCache.java b/src/org/openstreetmap/josm/data/osm/ChangesetCache.java
index 74840c6298..14b349b165 100644
--- a/src/org/openstreetmap/josm/data/osm/ChangesetCache.java
+++ b/src/org/openstreetmap/josm/data/osm/ChangesetCache.java
@@ -3,6 +3,7 @@ package org.openstreetmap.josm.data.osm;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -273,7 +274,7 @@ public final class ChangesetCache implements PreferenceChangedListener {
         synchronized (this) {
             reader = new OsmServerChangesetReader();
         }
-        List<Changeset> server = reader.queryChangesets(ChangesetQuery.forCurrentUser().beingOpen(true), null);
+        List<Changeset> server = UserIdentityManager.getInstance().isAnonymous() ? Collections.emptyList() : reader.queryChangesets(ChangesetQuery.forCurrentUser().beingOpen(true), null);
         Logging.info("{0} open changesets on server", server.size());
 
         DefaultChangesetCacheEvent e = new DefaultChangesetCacheEvent(this);
diff --git a/src/org/openstreetmap/josm/io/UploadStrategy.java b/src/org/openstreetmap/josm/io/UploadStrategy.java
index f1e0d2e5e4..f675c150f7 100644
--- a/src/org/openstreetmap/josm/io/UploadStrategy.java
+++ b/src/org/openstreetmap/josm/io/UploadStrategy.java
@@ -92,6 +92,6 @@ public enum UploadStrategy {
      * @param strategy the strategy to save
      */
     public static void saveToPreferences(UploadStrategy strategy) {
-        Config.getPref().put("osm-server.upload-strategy", strategy.getPreferenceValue());
+        Config.getPref().put("osm-server.upload-strategy", strategy != null ? strategy.getPreferenceValue() : null);
     }
 }
diff --git a/test/unit/org/openstreetmap/josm/actions/UploadActionTest.java b/test/unit/org/openstreetmap/josm/actions/UploadActionTest.java
new file mode 100644
index 0000000000..d30e23868f
--- /dev/null
+++ b/test/unit/org/openstreetmap/josm/actions/UploadActionTest.java
@@ -0,0 +1,100 @@
+package org.openstreetmap.josm.actions;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import java.awt.GraphicsEnvironment;
+import java.util.Collections;
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.command.AddPrimitivesCommand;
+import org.openstreetmap.josm.data.UserIdentityManager;
+import org.openstreetmap.josm.data.coor.LatLon;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.Node;
+import org.openstreetmap.josm.gui.MainApplication;
+import org.openstreetmap.josm.gui.io.UploadDialog;
+import org.openstreetmap.josm.gui.layer.OsmDataLayer;
+import org.openstreetmap.josm.gui.util.GuiHelper;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+import org.openstreetmap.josm.testutils.annotations.BasicPreferences;
+import org.openstreetmap.josm.testutils.mockers.WindowMocker;
+import org.openstreetmap.josm.tools.Logging;
+
+import mockit.Invocation;
+import mockit.Mock;
+import mockit.MockUp;
+
+/**
+ * Test class for {@link UploadAction}
+ * @author Taylor Smock
+ */
+@BasicPreferences
+class UploadActionTest {
+    // Only needed for layer cleanup. And user identity cleanup. And ensuring that data isn't accidentally uploaded.
+    @RegisterExtension
+    JOSMTestRules josmTestRules = new JOSMTestRules().main().projection().fakeAPI();
+
+    /**
+     * Non-regression test for JOSM #21476.
+     */
+    @Test
+    void testNonRegression21476() {
+        TestUtils.assumeWorkingJMockit();
+        Logging.clearLastErrorAndWarnings();
+        new WindowMocker();
+        new UploadDialogMock();
+        // Set up the preconditions. This test acts more like an integration test, in so far as it also tests
+        // unrelated code.
+        UserIdentityManager.getInstance().setAnonymous();
+        final DataSet testData = new DataSet();
+        MainApplication.getLayerManager().addLayer(new OsmDataLayer(testData, "testNonRegression21476", null));
+        final Node toAdd = new Node(new LatLon(20, 20));
+        toAdd.put("shop", "butcher");
+        final AddPrimitivesCommand command = new AddPrimitivesCommand(Collections.singletonList(toAdd.save()), testData);
+        command.executeCommand();
+        final UploadAction uploadAction = new UploadAction();
+        uploadAction.updateEnabledState();
+        assertTrue(uploadAction.isEnabled());
+        // Perform the actual "test" -- we don't want it to throw an exception
+        assertDoesNotThrow(() -> uploadAction.actionPerformed(null));
+        // Sync threads
+        GuiHelper.runInEDT(() -> {/* sync edt */});
+        try {
+            MainApplication.worker.submit(() -> {/* sync worker */}).get(1, TimeUnit.SECONDS);
+            assertTrue(Logging.getLastErrorAndWarnings().isEmpty());
+        } catch (Exception exception) {
+            fail(exception);
+        } finally {
+            Logging.clearLastErrorAndWarnings();
+        }
+    }
+
+    private static class UploadDialogMock extends MockUp<UploadDialog> {
+        @Mock
+        public void pack(final Invocation invocation) {
+            if (!GraphicsEnvironment.isHeadless()) {
+                invocation.proceed();
+            }
+        }
+
+        @Mock
+        public void setVisible(final Invocation invocation, final boolean visible) {
+            if (!GraphicsEnvironment.isHeadless()) {
+                invocation.proceed(visible);
+            }
+        }
+
+        @Mock
+        public final boolean isCanceled(final Invocation invocation) {
+            if (!GraphicsEnvironment.isHeadless()) {
+                return invocation.proceed();
+            }
+            return true;
+        }
+    }
+}