diff --git a/src/event.js b/src/event.js
index 54e08c8e7..4d7d6a895 100644
--- a/src/event.js
+++ b/src/event.js
@@ -202,8 +202,8 @@ jQuery.event = {
 
 		var i, cur, tmp, bubbleType, ontype, handle, special,
 			eventPath = [ elem || document ],
-			type = event.type || event,
-			namespaces = event.namespace ? event.namespace.split(".") : [];
+			type = core_hasOwn.call( event, "type" ) ? event.type : event,
+			namespaces = core_hasOwn.call( event, "namespace" ) ? event.namespace.split(".") : [];
 
 		cur = tmp = elem = elem || document;
 
diff --git a/test/unit/event.js b/test/unit/event.js
index c14740104..295a4b8d4 100644
--- a/test/unit/event.js
+++ b/test/unit/event.js
@@ -2663,3 +2663,17 @@ test( "Check order of focusin/focusout events", 2, function() {
 	input.off();
 });
 
+test( "String.prototype.namespace does not cause trigger() to throw (#13360)", function() {
+	expect( 1 );
+	var errored = false;
+
+	String.prototype.namespace = function() {};
+
+	try {
+		jQuery("<p>").trigger("foo.bar");
+	} catch( e ) {
+		errored = true;
+	}
+	equal( errored, false, "trigger() did not throw exception" );
+	delete String.prototype.namespace;
+});