diff --git a/dev/common.html b/dev/common.html
index 7d55a8fb..d6a398f0 100644
--- a/dev/common.html
+++ b/dev/common.html
@@ -93,6 +93,11 @@
   vConsole.setOption('log.maxLogNumber', 20);
   vConsole.setOption({ network: { maxNetworkNumber: 30 }});
   vConsole.setOption({ network: { b: 123 }}); // overwrite previous line
+  vConsole.setOption({ '__proto__': { a: 1 }, 'prototype': { b: 2 }, 'constructor': 3 });
+  vConsole.setOption('__proto__.noOrig', 1);
+  vConsole.setOption('prototype.noOrig', 2);
+  vConsole.setOption('constructor', () => { console.log('hack') });
+  vConsole.setOption('log.__proto__.noOrig', 1);
   console.log(vConsole.option);
 }
 
diff --git a/src/core/core.ts b/src/core/core.ts
index 843db2bf..481504ab 100644
--- a/src/core/core.ts
+++ b/src/core/core.ts
@@ -517,21 +517,32 @@ export class VConsole {
    * @example `setOption({ log: { maxLogNumber: 20 }})`: overwrite 'log' object.
    */
   public setOption(keyOrObj: any, value?: any) {
+    
     if (typeof keyOrObj === 'string') {
       // parse `a.b = val` to `a: { b: val }`
       const keys = keyOrObj.split('.');
       let opt: any = this.option;
-      for (let i = 0; i < keys.length - 1; i++) {
+      for (let i = 0; i < keys.length; i++) {
+        if (keys[i] === '__proto__' || keys[i] === 'constructor' || keys[i] === 'prototype') {
+          console.debug(`[vConsole] Cannot set \`${keys[i]}\` in \`vConsole.setOption()\`.`);
+          return;
+        }
         if (opt[keys[i]] === undefined) {
           opt[keys[i]] = {};
         }
+        if (i === keys.length - 1) {
+          opt[keys[i]] = value;
+        }
         opt = opt[keys[i]];
       }
-      opt[keys[keys.length - 1]] = value;
       this._triggerPluginsEvent('updateOption');
       this._updateComponentByOptions();
     } else if (tool.isObject(keyOrObj)) {
       for (let k in keyOrObj) {
+        if (k === '__proto__' || k === 'constructor' || k === 'prototype') {
+          console.debug(`[vConsole] Cannot set \`${k}\` in \`vConsole.setOption()\`.`);
+          continue;
+        }
         this.option[k] = keyOrObj[k];
       }
       this._triggerPluginsEvent('updateOption');