diff --git a/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts b/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts
index 7480075576..d0f81bea60 100644
--- a/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts
+++ b/packages/cli/src/ui/hooks/useQuotaAndFallback.test.ts
@@ -341,6 +341,46 @@ Your admin might have disabled the access. Contact them to enable the Preview Re
 
         expect(result.current.proQuotaRequest).toBeNull();
       });
+
+      it('should handle ModelNotFoundError with invalid model correctly', async () => {
+        const { result } = renderHook(() =>
+          useQuotaAndFallback({
+            config: mockConfig,
+            historyManager: mockHistoryManager,
+            userTier: UserTierId.FREE,
+            setModelSwitchedFromQuotaError: mockSetModelSwitchedFromQuotaError,
+            onShowAuthSelection: mockOnShowAuthSelection,
+          }),
+        );
+
+        const handler = setFallbackHandlerSpy.mock
+          .calls[0][0] as FallbackModelHandler;
+
+        let promise: Promise<FallbackIntent | null>;
+        const error = new ModelNotFoundError('model not found', 404);
+
+        act(() => {
+          promise = handler('invalid-model', 'gemini-2.5-pro', error);
+        });
+
+        const request = result.current.proQuotaRequest;
+        expect(request).not.toBeNull();
+        expect(request?.failedModel).toBe('invalid-model');
+        expect(request?.isModelNotFoundError).toBe(true);
+
+        const message = request!.message;
+        expect(message).toBe(
+          `Model "invalid-model" was not found or is invalid.
+/model to switch models.`,
+        );
+
+        act(() => {
+          result.current.handleProQuotaChoice('retry_always');
+        });
+
+        const intent = await promise!;
+        expect(intent).toBe('retry_always');
+      });
     });
   });
 
diff --git a/packages/cli/src/ui/hooks/useQuotaAndFallback.ts b/packages/cli/src/ui/hooks/useQuotaAndFallback.ts
index e00460eb15..60c91f3143 100644
--- a/packages/cli/src/ui/hooks/useQuotaAndFallback.ts
+++ b/packages/cli/src/ui/hooks/useQuotaAndFallback.ts
@@ -83,16 +83,21 @@ export function useQuotaAndFallback({
           `/auth to switch to API key.`,
         ].filter(Boolean);
         message = messageLines.join('\n');
-      } else if (
-        error instanceof ModelNotFoundError &&
-        VALID_GEMINI_MODELS.has(failedModel)
-      ) {
+      } else if (error instanceof ModelNotFoundError) {
         isModelNotFoundError = true;
-        const messageLines = [
-          `It seems like you don't have access to ${failedModel}.`,
-          `Your admin might have disabled the access. Contact them to enable the Preview Release Channel.`,
-        ];
-        message = messageLines.join('\n');
+        if (VALID_GEMINI_MODELS.has(failedModel)) {
+          const messageLines = [
+            `It seems like you don't have access to ${failedModel}.`,
+            `Your admin might have disabled the access. Contact them to enable the Preview Release Channel.`,
+          ];
+          message = messageLines.join('\n');
+        } else {
+          const messageLines = [
+            `Model "${failedModel}" was not found or is invalid.`,
+            `/model to switch models.`,
+          ];
+          message = messageLines.join('\n');
+        }
       } else {
         const messageLines = [
           `We are currently experiencing high demand.`,