diff --git a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/rules/WorkbenchContextExtension.java b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/rules/WorkbenchContextExtension.java
index 6a08dced2fe..cdbc5a9e887 100644
--- a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/rules/WorkbenchContextExtension.java
+++ b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/rules/WorkbenchContextExtension.java
@@ -30,6 +30,7 @@
 import org.eclipse.e4.ui.workbench.modeling.EModelService;
 import org.eclipse.e4.ui.workbench.swt.DisplayUISynchronize;
 import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -90,6 +91,15 @@ protected void dispose() {
 			wb.close();
 		}
 
+		// Dispose any remaining shells that were not cleaned up by wb.close(),
+		// such as PartRenderingEngine's limbo shell
+		Display display = Display.getDefault();
+		for (Shell shell : display.getShells()) {
+			if (!shell.isDisposed()) {
+				shell.dispose();
+			}
+		}
+
 		ContextInjectionFactory.setDefault(null);
 
 		// Workaround, enforce uninjection on the UIEventTopic provider from context