diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index 1cabf2cfd6..fc2403e1c1 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -345,6 +345,47 @@ class OptionsUtil {
 
     // Private
 
+    static async _addFieldTemplatesToOptions(options, additionSourceUrl) {
+        let addition = null;
+        for (const {options: profileOptions} of options.profiles) {
+            const fieldTemplates = profileOptions.anki.fieldTemplates;
+            if (fieldTemplates !== null) {
+                if (addition === null) {
+                    addition = await this._readFile(additionSourceUrl);
+                }
+                profileOptions.anki.fieldTemplates = this._addFieldTemplatesBeforeEnd(fieldTemplates, addition);
+            }
+        }
+    }
+
+    static async _addFieldTemplatesBeforeEnd(fieldTemplates, addition) {
+        const pattern = /[ \t]*\{\{~?>\s*\(\s*lookup\s*\.\s*"marker"\s*\)\s*~?\}\}/;
+        const newline = '\n';
+        let replaced = false;
+        fieldTemplates = fieldTemplates.replace(pattern, (g0) => {
+            replaced = true;
+            return `${addition}${newline}${g0}`;
+        });
+        if (!replaced) {
+            fieldTemplates += newline;
+            fieldTemplates += addition;
+        }
+        return fieldTemplates;
+    }
+
+    static async _readFile(url) {
+        url = chrome.runtime.getURL(url);
+        const response = await fetch(url, {
+            method: 'GET',
+            mode: 'no-cors',
+            cache: 'default',
+            credentials: 'omit',
+            redirect: 'follow',
+            referrerPolicy: 'no-referrer'
+        });
+        return await response.text();
+    }
+
     static _getStringHashCode(string) {
         let hashCode = 0;
 
@@ -423,47 +464,10 @@ class OptionsUtil {
     static async _updateVersion3(options) {
         // Version 3 changes:
         //  Pitch accent Anki field templates added.
-        let addition = null;
-        for (const {options: profileOptions} of options.profiles) {
-            const fieldTemplates = profileOptions.anki.fieldTemplates;
-            if (fieldTemplates !== null) {
-                if (addition === null) {
-                    addition = await this._updateVersion3GetAnkiFieldTemplates();
-                }
-                profileOptions.anki.fieldTemplates = this._addFieldTemplatesBeforeEnd(fieldTemplates, addition);
-            }
-        }
+        await this._addFieldTemplatesToOptions(options, '/bg/data/anki-field-templates-upgrade-v2.handlebars');
         return options;
     }
 
-    static async _updateVersion3GetAnkiFieldTemplates() {
-        const url = chrome.runtime.getURL('/bg/data/anki-field-templates-upgrade-v2.handlebars');
-        const response = await fetch(url, {
-            method: 'GET',
-            mode: 'no-cors',
-            cache: 'default',
-            credentials: 'omit',
-            redirect: 'follow',
-            referrerPolicy: 'no-referrer'
-        });
-        return await response.text();
-    }
-
-    static async _addFieldTemplatesBeforeEnd(fieldTemplates, addition) {
-        const pattern = /[ \t]*\{\{~?>\s*\(\s*lookup\s*\.\s*"marker"\s*\)\s*~?\}\}/;
-        const newline = '\n';
-        let replaced = false;
-        fieldTemplates = fieldTemplates.replace(pattern, (g0) => {
-            replaced = true;
-            return `${addition}${newline}${g0}`;
-        });
-        if (!replaced) {
-            fieldTemplates += newline;
-            fieldTemplates += addition;
-        }
-        return fieldTemplates;
-    }
-
     static _updateVersion4(options) {
         // Version 4 changes:
         //  Options conditions converted to string representations.