diff --git a/js/dms.js b/js/dms.js
index c615ee0..20e7197 100644
--- a/js/dms.js
+++ b/js/dms.js
@@ -398,7 +398,7 @@ function removeDuplicates(a) {
 	return a.filter(function(item) {
 			let type = typeof item;
 			if(type in prims)
-					return prims[type].hasOwnProperty(item) ? false : (prims[type][item] = true);
+					return Object.prototype.hasOwnProperty.call(prims.type, item) ? false : (prims[type][item] = true);
 			else
 					return objs.indexOf(item) >= 0 ? false : objs.push(item);
 	});