diff --git a/integration-tests/json-output.error.responses b/integration-tests/json-output.error.responses
index 84b363bd7d..51c15cee69 100644
--- a/integration-tests/json-output.error.responses
+++ b/integration-tests/json-output.error.responses
@@ -1,3 +1,2 @@
-{"method":"generateContent","response":{"candidates":[{"content":{"parts":[{"text":"{\n  \"reasoning\": \"The user is asking to read the content of a specific file and handle a potential error. This involves a single tool call (reading a file) and a defined error response, fitting the criteria for Low Operational Complexity (1 step).\",\n  \"model_choice\": \"flash\"\n}"}],"role":"model"},"finishReason":"STOP","index":0}],"usageMetadata":{"promptTokenCount":1235,"candidatesTokenCount":67,"totalTokenCount":1579,"promptTokensDetails":[{"modality":"TEXT","tokenCount":1235}],"thoughtsTokenCount":277}}}
 {"method":"generateContentStream","response":[{"candidates":[{"content":{"parts":[{"thought":true,"text":"**Investigating File Access**\n\nI'm currently focused on the challenge of reading a file. The path provided is `/gemini-cli/.integration-tests/1761766343238/json-output-error/path/to/nonexistent/file.txt`, and I'm anticipating an error. It's safe to assume the file doesn't exist, which I intend to handle by responding with \"File not found\" as instructed.\n\n\n"}],"role":"model"},"index":0}],"usageMetadata":{"promptTokenCount":12303,"totalTokenCount":12418,"promptTokensDetails":[{"modality":"TEXT","tokenCount":12303}],"thoughtsTokenCount":115}},{"candidates":[{"content":{"parts":[{"thought":true,"text":"**Analyzing Error Handling**\n\nI've attempted to read the specified file, expecting an error due to the \"nonexistent\" path. My plan is to catch the error thrown by the `read_file` tool. Upon receiving this error, I'll promptly return \"File not found.\" This is in line with the initial instructions and ensures appropriate error management for the user's intended functionality. I'm now testing the error response.\n\n\n"}],"role":"model"},"index":0}],"usageMetadata":{"promptTokenCount":12303,"totalTokenCount":12467,"promptTokensDetails":[{"modality":"TEXT","tokenCount":12303}],"thoughtsTokenCount":164}},{"candidates":[{"content":{"parts":[{"thoughtSignature":"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","functionCall":{"name":"read_file","args":{"absolute_path":"/gemini-cli/.integration-tests/1761766343238/json-output-error/path/to/nonexistent/file.txt"}}}],"role":"model"},"finishReason":"STOP","index":0}],"usageMetadata":{"promptTokenCount":12303,"candidatesTokenCount":58,"totalTokenCount":12525,"promptTokensDetails":[{"modality":"TEXT","tokenCount":12303}],"thoughtsTokenCount":164}}]}
 {"method":"generateContentStream","response":[{"candidates":[{"content":{"parts":[{"text":"File not found"}],"role":"model"},"finishReason":"STOP","index":0}],"usageMetadata":{"promptTokenCount":12588,"candidatesTokenCount":3,"totalTokenCount":12591,"promptTokensDetails":[{"modality":"TEXT","tokenCount":12588}]}}]}
diff --git a/packages/core/src/config/config.test.ts b/packages/core/src/config/config.test.ts
index f70f37d811..fed88f2af7 100644
--- a/packages/core/src/config/config.test.ts
+++ b/packages/core/src/config/config.test.ts
@@ -634,6 +634,19 @@ describe('Server Config (config.ts)', () => {
       expect(config.getUseModelRouter()).toBe(true);
       expect(config.getModel()).toBe(chosenModel);
     });
+
+    it('should NOT switch to auto model if cli provides specific model, even if router is enabled', async () => {
+      const config = new Config({
+        ...baseParams,
+        useModelRouter: true,
+        model: 'gemini-flash-latest',
+      });
+
+      await config.refreshAuth(AuthType.LOGIN_WITH_GOOGLE);
+
+      expect(config.getUseModelRouter()).toBe(true);
+      expect(config.getModel()).toBe('gemini-flash-latest');
+    });
   });
 
   describe('ContinueOnFailedApiCall Configuration', () => {
diff --git a/packages/core/src/config/config.ts b/packages/core/src/config/config.ts
index ca37e9cada..f721d74d9c 100644
--- a/packages/core/src/config/config.ts
+++ b/packages/core/src/config/config.ts
@@ -562,8 +562,6 @@ export class Config {
       if (this.model === DEFAULT_GEMINI_MODEL_AUTO) {
         this.model = DEFAULT_GEMINI_MODEL;
       }
-    } else if (this.useModelRouter && this.model === DEFAULT_GEMINI_MODEL) {
-      this.model = DEFAULT_GEMINI_MODEL_AUTO;
     }
 
     // Vertex and Genai have incompatible encryption and sending history with