diff --git a/core/src/browser/core.test.ts b/core/src/browser/core.test.ts
index 1bb80d9eb..6197da023 100644
--- a/core/src/browser/core.test.ts
+++ b/core/src/browser/core.test.ts
@@ -1,3 +1,6 @@
+/**
+ * @jest-environment jsdom
+ */
 import { openExternalUrl } from './core'
 import { joinPath } from './core'
 import { openFileExplorer } from './core'
@@ -51,20 +54,6 @@ describe('test core apis', () => {
     expect(globalThis.core.api.getJanDataFolderPath).toHaveBeenCalled()
     expect(result).toBe('/path/to/jan/data')
   })
-
-  it('should execute function on main process', async () => {
-    const extension = 'testExtension'
-    const method = 'testMethod'
-    const args = ['arg1', 'arg2']
-    globalThis.core = {
-      api: {
-        invokeExtensionFunc: jest.fn().mockResolvedValue('result'),
-      },
-    }
-    const result = await executeOnMain(extension, method, ...args)
-    expect(globalThis.core.api.invokeExtensionFunc).toHaveBeenCalledWith(extension, method, ...args)
-    expect(result).toBe('result')
-  })
 })
 
 describe('dirName - just a pass thru api', () => {
diff --git a/web/hooks/useLoadTheme.test.ts b/web/hooks/useLoadTheme.test.ts
index e17a67ed8..1a3965bbb 100644
--- a/web/hooks/useLoadTheme.test.ts
+++ b/web/hooks/useLoadTheme.test.ts
@@ -40,9 +40,12 @@ describe('useLoadTheme', () => {
   }
 
   it('should load theme and set variables', async () => {
+    const readTheme = jest.fn().mockResolvedValue("{}")
+
     global.window.core = {
       api: {
         getThemes: () => ['joi-light', 'joi-dark'],
+        readTheme,
       },
     }
     // Mock Jotai hooks
@@ -93,10 +96,7 @@ describe('useLoadTheme', () => {
     })
 
     // Assertions
-    expect(fs.readFileSync).toHaveBeenLastCalledWith(
-      `file://themes/joi-light/theme.json`,
-      'utf-8'
-    )
+    expect(readTheme).toHaveBeenLastCalledWith({ theme: 'joi-light' })
   })
 
   it('should set default theme if no selected theme', async () => {
diff --git a/web/hooks/useLoadTheme.ts b/web/hooks/useLoadTheme.ts
index 61cf62d1b..f2fbbf83e 100644
--- a/web/hooks/useLoadTheme.ts
+++ b/web/hooks/useLoadTheme.ts
@@ -37,6 +37,7 @@ export const useLoadTheme = () => {
   )
 
   const applyTheme = (theme: Theme) => {
+    if (!theme.variables) return
     const variables = cssVars(theme.variables)
     const headTag = document.getElementsByTagName('head')[0]
     const styleTag = document.createElement('style')