diff --git a/user/src/com/google/gwt/user/client/ui/Tree.java b/user/src/com/google/gwt/user/client/ui/Tree.java
index 70b1e73..a0afc91 100644
--- a/user/src/com/google/gwt/user/client/ui/Tree.java
+++ b/user/src/com/google/gwt/user/client/ui/Tree.java
@@ -541,7 +541,9 @@
         // Currently, the way we're using image bundles causes extraneous events
         // to be sunk on individual items' open/close images. This leads to an
         // extra event reaching the Tree, which we will ignore here.
-        if (DOM.eventGetCurrentTarget(event) == getElement()) {
+        // Also, ignore middle and right clicks here.
+        if ((DOM.eventGetCurrentTarget(event) == getElement())
+            && (event.getButton() == Event.BUTTON_LEFT)) {
           elementClicked(DOM.eventGetTarget(event));
         }
         break;