diff --git a/src/Merge.ts b/src/Merge.ts
index 8df692c..5700dea 100644
--- a/src/Merge.ts
+++ b/src/Merge.ts
@@ -47,6 +47,7 @@ const  handleDefaultBehavior = (originalObject: any, newObject: any, behavior?:
     if (originalTypeName === "Object" && newTypeName === "Object") { // built-in behavior
         // tslint:disable:forin
         for (const p in newObject) {
+            if (isPrototypePolluted(p)) continue
             originalObject[p] = processBehavior(originalObject[p], newObject[p], behavior);
         }
         // tslint:enable:forin
@@ -54,6 +55,10 @@ const  handleDefaultBehavior = (originalObject: any, newObject: any, behavior?:
     }
 };
 
+const isPrototypePolluted = (key: any) => {
+    return ['__proto__', 'constructor', 'prototype'].includes(key)
+}
+
 /**
  * Recursively merge two objects together.
  * @param originalObject The base object. Properties here will be overwritten
@@ -72,7 +77,7 @@ export const Merge = (originalObject: any, newObject: any, behavior?: IMergeBeha
             return definedBehaviorResults;
         }
     }
-
+    
     return handleDefaultBehavior(originalObject, newObject, behavior);
 };