diff --git a/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java b/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
index 044586e..5e39c9c 100644
--- a/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
+++ b/src/main/java/qupath/ext/instanseg/ui/InstanSegController.java
@@ -1,5 +1,6 @@
 package qupath.ext.instanseg.ui;
 
+import javafx.application.Platform;
 import javafx.beans.binding.Bindings;
 import javafx.beans.binding.BooleanBinding;
 import javafx.beans.binding.ObjectBinding;
@@ -341,6 +342,10 @@ private void updateInputChannels(ImageData<BufferedImage> imageData) {
         if (imageData == null) {
             return;
         }
+        if (!Platform.isFxApplicationThread()) {
+            Platform.runLater(() -> updateInputChannels(imageData));
+            return;
+        }
         // Store the checks without changing the current value
         inputChannelCache.snapshotChecks();
         // Update the items