Change distance between Chapter's number and Heading

Hi, in my document I have a structure like this:

1 Chap1

1.1 SubChap1

1.1.1 SubSubChap1




1.1.N SubSubChapN

Headings where N is 10 are written with correct spacing, but when N is greater there is a lot of space between the numeration and the heading, like this:

How can I fix this? Where can i find settings about spacing between numeration and headings?