Index: trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImageViewerDialogTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImageViewerDialogTest.java	(revision 18685)
+++ trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImageViewerDialogTest.java	(revision 18686)
@@ -21,4 +21,5 @@
 import javax.swing.JPanel;
 
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -44,8 +45,14 @@
 
     private ImageViewerDialog dialog;
+
     @BeforeEach
     void setup() {
         this.dialog = ImageViewerDialog.getInstance();
         this.dialog.displayImages(null);
+    }
+
+    @AfterEach
+    void tearDown() {
+        this.dialog.destroy();
     }
 
Index: trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImagesLoaderTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImagesLoaderTest.java	(revision 18685)
+++ trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/ImagesLoaderTest.java	(revision 18686)
@@ -10,25 +10,24 @@
 import java.util.List;
 
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.RegisterExtension;
 import org.openstreetmap.josm.TestUtils;
 import org.openstreetmap.josm.gui.MainApplication;
 import org.openstreetmap.josm.gui.layer.GpxLayer;
 import org.openstreetmap.josm.io.GpxReader;
-import org.openstreetmap.josm.testutils.JOSMTestRules;
-
-import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import org.openstreetmap.josm.testutils.annotations.BasicPreferences;
 
 /**
  * Unit tests of {@link ImagesLoader} class.
  */
+@BasicPreferences
 class ImagesLoaderTest {
 
-    /**
-     * We need prefs for this.
-     */
-    @RegisterExtension
-    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
-    public JOSMTestRules test = new JOSMTestRules().preferences();
+    @AfterEach
+    void tearDown() {
+        if (ImageViewerDialog.hasInstance()) {
+            ImageViewerDialog.getInstance().destroy();
+        }
+    }
 
     /**
Index: trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/WikimediaCommonsLoaderTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/WikimediaCommonsLoaderTest.java	(revision 18685)
+++ trunk/test/unit/org/openstreetmap/josm/gui/layer/geoimage/WikimediaCommonsLoaderTest.java	(revision 18686)
@@ -11,4 +11,5 @@
 import java.util.List;
 
+import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -29,4 +30,11 @@
     static void beforeAll() {
         HttpClient.setFactory(Http1Client::new);
+    }
+
+    @AfterEach
+    void tearDown() {
+        if (ImageViewerDialog.hasInstance()) {
+            ImageViewerDialog.getInstance().destroy();
+        }
     }