diff --git a/lib/workers/global/config/parse/env.spec.ts b/lib/workers/global/config/parse/env.spec.ts
index 7222c42a55a..5ac19acafd6 100644
--- a/lib/workers/global/config/parse/env.spec.ts
+++ b/lib/workers/global/config/parse/env.spec.ts
@@ -314,7 +314,8 @@ describe('workers/global/config/parse/env', () => {
         RENOVATE_X_DELETE_CONFIG_FILE: 'true',
         RENOVATE_X_S3_ENDPOINT: 'endpoint',
         RENOVATE_X_S3_PATH_STYLE: 'true',
-        RENOVATE_X_REPO_CACHE_FORCE_LOCAL: 'true',
+        // NOTE that a non-empty string is treated as `true`
+        RENOVATE_X_REPO_CACHE_FORCE_LOCAL: 'enabled',
       };
       const config = await env.getConfig(envParam);
       expect(config).toMatchObject({
@@ -330,6 +331,14 @@ describe('workers/global/config/parse/env', () => {
       });
     });
 
+    it('does not migrate empty RENOVATE_X_REPO_CACHE_FORCE_LOCAL', async () => {
+      const envParam: NodeJS.ProcessEnv = {
+        RENOVATE_X_REPO_CACHE_FORCE_LOCAL: '',
+      };
+      const config = await env.getConfig(envParam);
+      expect(config.repositoryCacheForceLocal).toBeUndefined();
+    });
+
     describe('RENOVATE_CONFIG tests', () => {
       let processExit: MockInstance<(code?: number | string | null) => never>;
 
diff --git a/lib/workers/global/config/parse/env.ts b/lib/workers/global/config/parse/env.ts
index 2375ba39c75..d74af8d0b3f 100644
--- a/lib/workers/global/config/parse/env.ts
+++ b/lib/workers/global/config/parse/env.ts
@@ -1,4 +1,4 @@
-import { isArray } from '@sindresorhus/is';
+import { isArray, isNonEmptyString } from '@sindresorhus/is';
 import JSON5 from 'json5';
 import { getOptions } from '../../../../config/options/index.ts';
 import type { AllConfig } from '../../../../config/types.ts';
@@ -117,6 +117,9 @@ function massageConvertedExperimentalVars(
       // special case to use a more consistent prefix with other `repositoryCache` options
       if (key === 'RENOVATE_X_REPO_CACHE_FORCE_LOCAL') {
         newKey = 'RENOVATE_REPOSITORY_CACHE_FORCE_LOCAL';
+        if (isNonEmptyString(env[key])) {
+          env[key] = 'true';
+        }
       }
 
       result[newKey] = env[key];