@@ -515,8 +515,14 @@
 		[desc appendFormat: @"?%@", query];
 
 	if (fragment != nil)
 		[desc appendFormat: @"#%@", fragment];
 
+	/*
+	 * Class swizzle the string to be immutable. We declared the return type
+	 * to be OFString*, so it can't be modified anyway. But not swizzling it
+	 * would create a real copy each time -[copy] is called.
+	 */
+	desc->isa = [OFString class];
 	return desc;
 }
 @end