point in polygon - How to find all features in one table that intersect features in another table in PostGIS?

I have two tables, boundary polygon table and location point table. I need to find all boundary polygons that contain at least 1 location point. What is the proper way to do this in PostGIS?

I tried:

SELECT *
FROM boundary, location
WHERE ST_Intersects(boundary.geom, location.geom)

But this returns each combination of boundary and location that intersect, when all I want is the boundary returned once. For example, I got 76 results, but only have 10 boundary entries. Do you know a better way to do this?

Answer

Would be more efficient with EXISTS I think since it can stop after first positive. Though Martin's answer should work as well

SELECT boundary.*
  FROM boundary
 WHERE EXISTS (SELECT location.geom 

   FROM location 
    WHERE ST_Intersects(boundary.geom,location.geom) );