Question: I am trying to round the corners of a custom shape, but it is just straightening the original curves out.

*Note: This is in Illustrator CS5*

**Here is the shape before the effect:**

[![enter image description here](https://i.stack.imgur.com/luohd.png)](https://i.stack.imgur.com/luohd.png)

The 3 "corners should be rounded".

**Here is what happens when I use the effect:**

[![enter image description here](https://i.stack.imgur.com/3jyfQ.png)](https://i.stack.imgur.com/3jyfQ.png)

**How can I preserve the curves, and just round the actual corners?**

Answer: 
**Purely for comparison’s sake**, I thought it would be good to show what Adobe Illustrator CC (in this case, I am using v2017) can do:

[![enter image description here](https://i.stack.imgur.com/8d2hQ.gif)](https://i.stack.imgur.com/8d2hQ.gif)

1. With the selection tool, select your entire path
2. On a Mac, hold down `COMMAND` key (`CONTROL` on Win).
3. Click and drag on the corner radius circle icons that appear
4. You can optionally select a specific point and just round the corner for that part of your shape

Double click one of the circles for corner options:

[![](https://i.stack.imgur.com/3ci1E.png)](https://i.stack.imgur.com/3ci1E.png)
The simple way:
Create additional anchor points around cornes (as it was mentioned at first answer), then apply Round Corner effect as usual.