diff --git a/ext/bg/js/yomichan.js b/ext/bg/js/yomichan.js
index cbbcae63..7a26d6c7 100644
--- a/ext/bg/js/yomichan.js
+++ b/ext/bg/js/yomichan.js
@@ -189,37 +189,37 @@ window.yomichan = new class {
         }
     }
 
-    onMessage(request, sender, callback) {
-        const handlers = new class {
-            optionsGet({callback}) {
+    onMessage({action, params}, sender, callback) {
+        const handlers = {
+            optionsGet: ({callback}) => {
                 promiseCallback(optionsLoad(), callback);
-            }
+            },
 
-            kanjiFind({text, callback}) {
+            kanjiFind: ({text, callback}) => {
                 promiseCallback(this.kanjiFind(text), callback);
-            }
+            },
 
-            termsFind({text, callback}) {
+            termsFind: ({text, callback}) => {
                 promiseCallback(this.termsFind(text), callback);
-            }
+            },
 
-            templateRender({template, data, callback}) {
+            templateRender: ({template, data, callback}) => {
                 promiseCallback(this.templateRender(template, data), callback);
-            }
+            },
 
-            definitionAdd({definition, mode, callback}) {
+            definitionAdd: ({definition, mode, callback}) => {
                 promiseCallback(this.definitionAdd(definition, mode), callback);
-            }
+            },
 
-            definitionsAddable({definitions, modes, callback}) {
+            definitionsAddable: ({definitions, modes, callback}) => {
                 promiseCallback(this.definitionsAddable(definitions, modes), callback);
             }
         };
 
-        const {action, params} = request, method = handlers[action];
-        if (typeof(method) === 'function') {
+        const handler = handlers[action];
+        if (handler) {
             params.callback = callback;
-            method.call(this, params);
+            handler(params);
         }
 
         return true;
diff --git a/ext/fg/js/display-frame.js b/ext/fg/js/display-frame.js
index 41c2fb53..59032d0c 100644
--- a/ext/fg/js/display-frame.js
+++ b/ext/fg/js/display-frame.js
@@ -57,23 +57,24 @@ window.displayFrame = new class extends Display {
     }
 
     onMessage(e) {
-        const handlers = new class {
-            showTermDefs({definitions, options, context}) {
+        const handlers = {
+            showTermDefs: ({definitions, options, context}) => {
                 this.showTermDefs(definitions, options, context);
-            }
+            },
 
-            showKanjiDefs({definitions, options, context}) {
+            showKanjiDefs: ({definitions, options, context}) => {
                 this.showKanjiDefs(definitions, options, context);
-            }
+            },
 
-            showOrphaned() {
+            showOrphaned: () => {
                 this.showOrphaned();
             }
         };
 
-        const {action, params} = e.originalEvent.data, method = handlers[action];
-        if (typeof(method) === 'function') {
-            method.call(this, params);
+        const {action, params} = e.originalEvent.data;
+        const handler = handlers[action];
+        if (handler) {
+            handler(params);
         }
     }
 };
diff --git a/ext/fg/js/driver.js b/ext/fg/js/driver.js
index 036dc2d8..2324e6b2 100644
--- a/ext/fg/js/driver.js
+++ b/ext/fg/js/driver.js
@@ -116,8 +116,8 @@ window.driver = new class {
     }
 
     onBgMessage({action, params}, sender, callback) {
-        const handlers = new class {
-            optionsSet(options) {
+        const handlers = {
+            optionsSet: options => {
                 this.options = options;
                 if (!this.options.enable) {
                     this.searchClear();
@@ -125,9 +125,9 @@ window.driver = new class {
             }
         };
 
-        const method = handlers[action];
-        if (typeof(method) === 'function') {
-            method.call(this, params);
+        const handler = handlers[action];
+        if (handler) {
+            handler(params);
         }
 
         callback();