diff --git a/src/main/java/org/scijava/ui/AbstractUserInterface.java b/src/main/java/org/scijava/ui/AbstractUserInterface.java
index a3894158b..74fb56793 100644
--- a/src/main/java/org/scijava/ui/AbstractUserInterface.java
+++ b/src/main/java/org/scijava/ui/AbstractUserInterface.java
@@ -29,6 +29,7 @@
 
 package org.scijava.ui;
 
+import java.lang.reflect.InvocationTargetException;
 import java.util.List;
 
 import org.scijava.display.Display;
@@ -79,9 +80,11 @@ public abstract class AbstractUserInterface extends AbstractRichPlugin
 
 	@Override
 	public void show() {
-		if (visible) return;
-		createUI();
-		visible = true;
+		runOnDispatchThreadIfNeeded(() -> {
+			if (visible) return;
+			createUI();
+			visible = true;
+		});
 	}
 
 	@Override
@@ -112,32 +115,29 @@ public void show(final Display<?> display) {
 			return;
 		}
 
-		final List<PluginInfo<DisplayViewer<?>>> viewers =
-			uiService.getViewerPlugins();
-
-		DisplayViewer<?> displayViewer = null;
-		for (final PluginInfo<DisplayViewer<?>> info : viewers) {
-			// check that viewer can actually handle the given display
-			final DisplayViewer<?> viewer = pluginService.createInstance(info);
-			if (viewer == null) continue;
-			if (!viewer.canView(display)) continue;
-			if (!viewer.isCompatible(this)) continue;
-			displayViewer = viewer;
-			break; // found a suitable viewer; we are done
-		}
-		if (displayViewer == null) {
-			log.warn("For UI '" + getClass().getName() +
-				"': no suitable viewer for display: " + display);
-			return;
-		}
-
-		final DisplayViewer<?> finalViewer = displayViewer;
-		threadService.queue(new Runnable() {
-			@Override
-			public void run() {
-				uiService.addDisplayViewer(finalViewer);
-				finalViewer.view(AbstractUserInterface.this, display);
+		runOnDispatchThreadIfNeeded(() -> {
+			final List<PluginInfo<DisplayViewer<?>>> viewers =
+				uiService.getViewerPlugins();
+
+			DisplayViewer<?> displayViewer = null;
+			for (final PluginInfo<DisplayViewer<?>> info : viewers) {
+				// check that viewer can actually handle the given display
+				final DisplayViewer<?> viewer = pluginService.createInstance(info);
+				if (viewer == null) continue;
+				if (!viewer.canView(display)) continue;
+				if (!viewer.isCompatible(this)) continue;
+				displayViewer = viewer;
+				break; // found a suitable viewer; we are done
+			}
+			if (displayViewer == null) {
+				log.warn("For UI '" + getClass().getName() +
+					"': no suitable viewer for display: " + display);
+				return;
 			}
+
+			final DisplayViewer<?> finalViewer = displayViewer;
+			uiService.addDisplayViewer(finalViewer);
+			finalViewer.view(AbstractUserInterface.this, display);
 		});
 	}
 
@@ -170,4 +170,21 @@ public void restoreLocation() {
 	protected void createUI() {
 		restoreLocation();
 	}
+
+	// -- Helper methods --
+
+	private void runOnDispatchThreadIfNeeded(Runnable r) {
+		if (requiresEDT()) {
+			try {
+				// Note: Blocks until execution is complete!
+				threadService.invoke(r);
+			}
+			catch (InterruptedException | InvocationTargetException e) {
+				throw new RuntimeException(e);
+			}
+		}
+		else {
+			r.run();
+		}
+	}
 }
diff --git a/src/main/java/org/scijava/ui/DefaultUIService.java b/src/main/java/org/scijava/ui/DefaultUIService.java
index ff5663f91..c4b1e5bac 100644
--- a/src/main/java/org/scijava/ui/DefaultUIService.java
+++ b/src/main/java/org/scijava/ui/DefaultUIService.java
@@ -162,25 +162,10 @@ public void showUI(final String name) {
 	@Override
 	public void showUI(final UserInterface ui) {
 		log.debug("Launching user interface: " + ui.getClass().getName());
-		Runnable showUI = () -> {
-			ui.show();
-			// NB: Also show all the current displays.
-			for (final Display<?> display : displayService.getDisplays()) {
-				ui.show(display);
-			}
-		};
-
-		// Dispatch on EDT if necessary
-		if (ui.requiresEDT()) {
-			try {
-				threadService.invoke(showUI);
-			}
-			catch (InterruptedException | InvocationTargetException e) {
-				throw new RuntimeException(e);
-			}
-		}
-		else {
-			showUI.run();
+		ui.show();
+		// NB: Also show all the current displays.
+		for (final Display<?> display : displayService.getDisplays()) {
+			ui.show(display);
 		}
 		eventService.publish(new UIShownEvent(ui));
 	}