diff --git a/packages/vitest/src/utils/coverage.ts b/packages/vitest/src/utils/coverage.ts
index 1983d9dfab77..7e45f6db0780 100644
--- a/packages/vitest/src/utils/coverage.ts
+++ b/packages/vitest/src/utils/coverage.ts
@@ -263,14 +263,16 @@ function resolveConfig(configModule: any) {
     if (mod.$type === 'object')
       return mod
 
-    if (mod.$type === 'function-call') {
-      // "export default defineConfig({ test: {...} })"
-      if (mod.$args[0].$type === 'object')
-        return mod.$args[0]
-
-      // "export default defineConfig(() => ({ test: {...} }))"
-      if (mod.$args[0].$type === 'arrow-function-expression' && mod.$args[0].$body.$type === 'object')
-        return mod.$args[0].$body
+    // "export default defineConfig(...)"
+    let config = resolveDefineConfig(mod)
+    if (config)
+      return config
+
+    // "export default mergeConfig(..., defineConfig(...))"
+    if (mod.$type === 'function-call' && mod.$callee === 'mergeConfig') {
+      config = resolveMergeConfig(mod)
+      if (config)
+        return config
     }
   }
   catch (error) {
@@ -280,3 +282,33 @@ function resolveConfig(configModule: any) {
 
   throw new Error('Failed to update coverage thresholds. Configuration file is too complex.')
 }
+
+function resolveDefineConfig(mod: any) {
+  if (mod.$type === 'function-call' && mod.$callee === 'defineConfig') {
+    // "export default defineConfig({ test: {...} })"
+    if (mod.$args[0].$type === 'object')
+      return mod.$args[0]
+
+    if (mod.$args[0].$type === 'arrow-function-expression') {
+      if (mod.$args[0].$body.$type === 'object') {
+        // "export default defineConfig(() => ({ test: {...} }))"
+        return mod.$args[0].$body
+      }
+
+      // "export default defineConfig(() => mergeConfig({...}, ...))"
+      const config = resolveMergeConfig(mod.$args[0].$body)
+      if (config)
+        return config
+    }
+  }
+}
+
+function resolveMergeConfig(mod: any): any {
+  if (mod.$type === 'function-call' && mod.$callee === 'mergeConfig') {
+    for (const arg of mod.$args) {
+      const config = resolveDefineConfig(arg)
+      if (config)
+        return config
+    }
+  }
+}
diff --git a/test/coverage-test/option-tests/thresholds-auto-update.test.ts b/test/coverage-test/option-tests/thresholds-auto-update.test.ts
new file mode 100644
index 000000000000..12e5620a6602
--- /dev/null
+++ b/test/coverage-test/option-tests/thresholds-auto-update.test.ts
@@ -0,0 +1,162 @@
+import { parseModule } from 'magicast'
+import type { CoverageMap } from 'istanbul-lib-coverage'
+import { createCoverageSummary } from 'istanbul-lib-coverage'
+
+import { expect, test } from 'vitest'
+import { defineConfig } from 'vitest/config'
+import { BaseCoverageProvider } from 'vitest/coverage'
+
+const initialThresholds = { lines: 1, branches: 2, functions: 3, statements: 4 }
+const coveredThresholds = { lines: 50, branches: 60, functions: 70, statements: 80 }
+const initialConfig = JSON.stringify(defineConfig({
+  test: {
+    coverage: {
+      thresholds: initialThresholds,
+    },
+  },
+}), null, 2)
+
+test('updates thresholds on "export default {..}"', async () => {
+  const config = parseModule(`export default ${initialConfig}`)
+
+  const updatedConfig = await updateThresholds(config)
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default {
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 50,
+            "branches": 60,
+            "functions": 70,
+            "statements": 80
+          }
+        }
+      }
+    }"
+  `)
+})
+
+test('updates thresholds on "export default defineConfig({...})"', async () => {
+  const config = parseModule(`export default defineConfig(${initialConfig})`)
+
+  const updatedConfig = await updateThresholds(config)
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default defineConfig({
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 50,
+            "branches": 60,
+            "functions": 70,
+            "statements": 80
+          }
+        }
+      }
+    })"
+  `)
+})
+
+test('updates thresholds on "export default defineConfig(() => ({...}))"', async () => {
+  const config = parseModule(`export default defineConfig(() => (${initialConfig}))`)
+
+  const updatedConfig = await updateThresholds(config)
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default defineConfig(() => ({
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 50,
+            "branches": 60,
+            "functions": 70,
+            "statements": 80
+          }
+        }
+      }
+    }))"
+  `)
+})
+
+test('updates thresholds on "export default mergeConfig({...}, defineConfig({...}))"', async () => {
+  const config = parseModule(`export default mergeConfig(baseConfig, defineConfig(${initialConfig}))`)
+
+  const updatedConfig = await updateThresholds(config)
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default mergeConfig(baseConfig, defineConfig({
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 50,
+            "branches": 60,
+            "functions": 70,
+            "statements": 80
+          }
+        }
+      }
+    }))"
+  `)
+})
+
+test('updates thresholds on "export default defineConfig(() => mergeConfig({...}, defineConfig({...})))"', async () => {
+  const config = parseModule(`export default defineConfig((configEnv) => mergeConfig(baseConfig, defineConfig(${initialConfig})))`)
+
+  const updatedConfig = await updateThresholds(config)
+
+  expect(updatedConfig).toMatchInlineSnapshot(`
+    "export default defineConfig((configEnv) => mergeConfig(baseConfig, defineConfig({
+      "test": {
+        "coverage": {
+          "thresholds": {
+            "lines": 50,
+            "branches": 60,
+            "functions": 70,
+            "statements": 80
+          }
+        }
+      }
+    })))"
+  `)
+})
+
+test('throws when configuration is too complex to analyze', async () => {
+  const config = parseModule(`
+import config from "./some-path"
+export default config
+  `)
+
+  await expect(updateThresholds(config)).rejects.toThrowErrorMatchingInlineSnapshot(`[Error: Failed to update coverage thresholds. Configuration file is too complex.]`)
+})
+
+async function updateThresholds(configurationFile: ReturnType<typeof parseModule>) {
+  const summaryData = { total: 0, covered: 0, skipped: 0 }
+  const thresholds = [{
+    name: 'global',
+    thresholds: initialThresholds,
+    coverageMap: {
+      getCoverageSummary: () => createCoverageSummary({
+        lines: { pct: coveredThresholds.lines, ...summaryData },
+        statements: { pct: coveredThresholds.statements, ...summaryData },
+        branches: { pct: coveredThresholds.branches, ...summaryData },
+        functions: { pct: coveredThresholds.functions, ...summaryData },
+      }),
+    } as CoverageMap,
+  }]
+
+  return new Promise((resolve, reject) => {
+    const provider = new BaseCoverageProvider()
+
+    try {
+      provider.updateThresholds({
+        thresholds,
+        configurationFile,
+        onUpdate: () => resolve(configurationFile.generate().code),
+      })
+    }
+    catch (error) {
+      reject(error)
+    }
+  })
+}
diff --git a/test/coverage-test/testing-options.mjs b/test/coverage-test/testing-options.mjs
index 069632058a96..e7727ff6b95d 100644
--- a/test/coverage-test/testing-options.mjs
+++ b/test/coverage-test/testing-options.mjs
@@ -194,6 +194,13 @@ const testCases = [
       include: ['coverage-report-tests/merge-reports.test.ts'],
     },
   },
+  {
+    testConfig: {
+      name: 'thresholds autoUpdate',
+      include: ['option-tests/thresholds-auto-update.test.ts'],
+      coverage: { provider: 'v8', enabled: false },
+    },
+  },
 ]
 
 for (const provider of ['v8', 'istanbul']) {