diff --git a/src/utils/providerEnvSelection.test.ts b/src/utils/providerEnvSelection.test.ts
index 23849269..2c4c6127 100644
--- a/src/utils/providerEnvSelection.test.ts
+++ b/src/utils/providerEnvSelection.test.ts
@@ -100,4 +100,17 @@ describe('filterSettingsEnvForExplicitProvider', () => {
       }),
     ).toEqual({ OTHER: 'keep-me' })
   })
+
+  test('preserves explicit ollama startup intent by stripping OpenAI routing settings', () => {
+    process.env.CLAUDE_CODE_EXPLICIT_PROVIDER = 'ollama'
+
+    expect(
+      filterSettingsEnvForExplicitProvider({
+        OPENAI_BASE_URL: 'https://api.openai.com/v1',
+        OPENAI_MODEL: 'gpt-4o',
+        OPENAI_API_KEY: 'sk-test',
+        OTHER: 'keep-me',
+      }),
+    ).toEqual({ OTHER: 'keep-me' })
+  })
 })
diff --git a/src/utils/providerEnvSelection.ts b/src/utils/providerEnvSelection.ts
index c11cb9d6..2603188a 100644
--- a/src/utils/providerEnvSelection.ts
+++ b/src/utils/providerEnvSelection.ts
@@ -41,6 +41,13 @@ export function filterSettingsEnvForExplicitProvider(
     delete filtered[key]
   }
 
+  if (explicitProvider === 'ollama') {
+    delete filtered.OPENAI_BASE_URL
+    delete filtered.OPENAI_MODEL
+    delete filtered.OPENAI_API_KEY
+    return filtered
+  }
+
   if (explicitProvider === 'github') {
     if (!isGithubModel(filtered.OPENAI_MODEL)) {
       delete filtered.OPENAI_MODEL