diff --git a/core/js/js.js b/core/js/js.js
index 808c2c28ad..7ff010eca0 100644
--- a/core/js/js.js
+++ b/core/js/js.js
@@ -1213,7 +1213,7 @@ $.fn.filterAttr = function(attr_name, attr_value) {
 function humanFileSize(size, skipSmallSizes) {
 	var humanList = ['B', 'kB', 'MB', 'GB', 'TB'];
 	// Calculate Log with base 1024: size = 1024 ** order
-	var order = size?Math.floor(Math.log(size) / Math.log(1024)):0;
+	var order = size > 0 ? Math.floor(Math.log(size) / Math.log(1024)) : 0;
 	// Stay in range of the byte sizes that are defined
 	order = Math.min(humanList.length - 1, order);
 	var readableFormat = humanList[order];
diff --git a/core/js/tests/specs/coreSpec.js b/core/js/tests/specs/coreSpec.js
index d283839d7e..159c374366 100644
--- a/core/js/tests/specs/coreSpec.js
+++ b/core/js/tests/specs/coreSpec.js
@@ -465,6 +465,8 @@ describe('Core base tests', function() {
 			it('renders file sizes with the correct unit', function() {
 				var data = [
 					[0, '0 B'],
+					["0", '0 B'],
+					["A", 'NaN B'],
 					[125, '125 B'],
 					[128000, '125 kB'],
 					[128000000, '122.1 MB'],