diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index a2fc9494..eb91e3d7 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -3615,7 +3615,7 @@ getJasmineRequireObj().ExceptionFormatter = function(j$) {
       const result = {};
       let empty = true;
 
-      for (const prop in error) {
+      for (const prop of Object.keys(error)) {
         if (ignoredProperties.includes(prop)) {
           continue;
         }