diff --git a/guacamole-common-js/src/main/webapp/modules/Mouse.js b/guacamole-common-js/src/main/webapp/modules/Mouse.js
index 379458b0b..6aaf77fe0 100644
--- a/guacamole-common-js/src/main/webapp/modules/Mouse.js
+++ b/guacamole-common-js/src/main/webapp/modules/Mouse.js
@@ -546,10 +546,12 @@ Guacamole.Mouse.Event = function MouseEvent(type, state, events) {
 
     /**
      * The current mouse state at the time this event was fired.
+     * The state object is cloned so as not to be affected by subsequent events
+     * that will have their own dedicated Guacamole.Mouse.Event instance.
      *
      * @type {!Guacamole.Mouse.State}
      */
-    this.state = state;
+    this.state = { ...state };
 
     /**
      * @inheritdoc